Mobile workforce app saves businesses almost £4m

An award-winning mobile workforce management app aimed at engineers and builders out on the road has saved its customers almost £4m since it was launched in November 2011.

MyMobileWorkers, developed by Momote is the UK’s first pay as you go workforce management app which allows a workforce to accurately log any kind of job information on a mobile phone device which is then fed into a back office system

The app eliminates the need for paper job sheets, saving time for both engineers out on the road as well as the administration time taken to process them.

Altogether the app has saved more than 280,000 hours for its customers, breaking down to £3,455,611 in field service hours and £292,782 in administration time. It has also saved customers £8,393 on the 1,721,900 sheets of paper they didn’t need to use, equating to nearly a tonne. Every tonne of recycled paper saves around 17 trees.

The app is used by companies across a variety of sectors including building maintenance, waste recycling and engineering across the North West and UK.

Suffolk based building maintenance company MC Contracts uses the pay-as-you-go mobile workforce management app to assign, track and record job details for its engineers.

The app has already saved the company 45 man-hours a week as engineers no longer have to travel to and from the head office to drop off paper job sheets. Jobs are assigned in the morning via the mobile device and engineers can get straight out on the road.

Mark Calver, managing director of MC Contracts, whose key contract is with a major housing association, said: “Investing in this new technology has been a huge boost to our company, the unique model of paying per job has meant this is affordable.

“Historically we’ve looked at similar systems and they have been cost prohibitive.

“This model of paying per maintenance visit has allowed us to improve the speed with which we can attend maintenance call-outs which benefits us as a business and also benefits the customer.

"The app means the engineer can access all the correct job information instantly at the touch of a button which saves them having to contact the office repeatedly for job details.”

Graham Whistance, founder of MyMobileWorkers, said: “Saving businesses money and increasing efficiency is one of the main reasons we launched MyMobileWorkers in the first place and the results speak for themselves.

“Mobile apps such as ours allow small businesses to get more time out of their day and spend it on higher value work.

“Tough economic conditions have highlighted the need for companies to pay close attention to the way in which their mobile workforce is managed and the pay as you go aspect of MyMobileWorkers makes it inclusive for businesses of all sizes.”

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Benefits of Using Silica Fume in Concrete

Silica Fume has been used all over the world for many years in the area where high strength and durable concrete were required. Silica Fume improves the characteristics of both fresh and hard concrete.

1. Reduce of Concrete Permeability

For provision of a concrete resistant to the most aggressive environment, the most important property is the permeability.

Lower the ingress of movement of water or chemicals; lower the deterious reactions such as sulfate attack, reinforcement corrosion…
The reaction between Silica Fume and the calcium hydroxide, released as the cement hydrates, provides a dense impermeable pore structure. Although the total porosity of the Silica Fume concrete is similar to the OPC concrete the average pore size is much finer, conducting to a large reduction of permeability.

2. Improvement of concrete mechanical Performances

The Silica Fume reacts with the cement paste to form additional strong Calcium Silicate Hydrate (CSH) providing higher strength.
Silica Fume reduces bleeding and enhances the cement paste bond to the aggregates. Thanks to its pozzolanic effect (reaction with Ca(OH)2 ), and therefore to the strength improvement, Silica Fume can be used to reduce to the cement content of the mix.
In addition of the cost saving benefit, this will reduce the total heat of hydration and can improve the performances of the concrete in terms of chemical resistance.

3. Improvement of Concrete Sulfate resistance

Prior to develop the advantages of using Silica Fume to improve the concrete sulfate resistance, it may be interesting to highlight the basics form of sulfate attacks and the properties of sulfate resisting cement.

The use and deterioration of concrete in environments containing sulfates has led to the development of special sulfate resisting cements.
It has also spawned significant research into the use of supplementary cementitious materials to improve sulfate resistance.
The utility of Silica Fume for enhancing the resistance of concrete to sulfate attack has been widely studied.
Sulfate resisting cements (type V) have a low C3A content to minimize the risk off sulfate attack. However, this does not necessarily provide immunity:
- as certain sulfate react with hydrated lime and the calcium silicate hydrate the sulfate resisting cement provide less protection than expected.
- Low C3A cements are more susceptible to reinforcement corrosion attack.
The basic forms of sulfate attack are the following:
The reactive aluminates in the cement will react with the gypsum in cement during hydration. This process is harmless as the ettringite does not produce expansive forces and is stable in sulfate solutions.
If the quantity of reactive aluminates in the cement is too high, then their hydrate form will be available to react with sulfates after the cement has hardened.

This will produce expansive ettringite and cracking of the concrete.

Aluminate Hydrate + Calcium Hydroxide + sulfate + water => Ettringite.

The second principle cause attack is the acid interaction of sulfates ions and calcium hydroxide, causing gypsum formation.

Calcium Hydroxide + sulfate + water => Gypsum

It has been shown that the cation (calcium, Magnesium, Aluminium, Ammonium) of the sulfate salt affects the type and the severity of the attack.

4. Improvement of Reinforcement Corrosion Protection

In a marine structure, the performances of the concrete in terms of sulfate resistance must be taken into consideration for concrete design but the resistance to chlorides diffusion through the concrete is generally a main concern as well.

Some studies conducted in several countries proved that Type 1 cements (with high C3A content) blended with Silica Fume used in combination with a high range water reducer provide high durable performance against chloride-induced reinforcement corrosion and against sulfate attack.

The main reasons of this result can be summarize as follows:
- Silica Fume reduces the permeability of the concrete. Water and chemicals ingress are thus reduced.
- The ability of high C3A cement to complex with chlorides results in the formation of insoluble compound, able to reduce the mobility of free chloride ion to the reinforcement-concrete surface.

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Manufacturing Engineering Scholarships

Students pursuing a major in manufacturing engineering receive core curriculum in science and mathematics. Within the specialty students study more focused components of a manufacturing environment including technological and production processes associated with all aspects of manufacturing.

The job of a Manufacturing Engineer includes designing, analyzing and implementing innovative systems and processes that streamline the production of materials and goods. Professionals may be asked to consider manufacturing from a wide perspective, including financial, technical, and labor related aspects.

Part of the mission behind the Society of Manufacturing Engineers (SME) is to provide monetary and professional support to member students. To those ends the organization sponsors a heady array of scholarships for students at all levels of manufacturing engineering studies. A few include:

Caterpillar Scholars Awards are offered to high school seniors enrolling in a manufacturing engineering major at a four-year college. Preference is given to minority students with proven academic talent.
Phoenix Scholarships go to students pursuing manufacturing engineering in a college in Arizona.
E. Wayne Kay Community College Scholarships are available to manufacturing engineering students attending a two-year community college program. Eligible applicants must have at least a 3.0 GPA to be considered.
High school students who already are engaged in manufacturing engineering activities and are members of the Junior Engineering Technical Society (JETS) not only have access to extracurricular know-how and industry-related activities, but they also are eligible for scholarships. The Next Generation Scholarship Fund is designed to attract those graduating high school students with superior academic aptitude especially in engineering.

College Scholarships

The College of Engineering and Architecture at the University of North Dakota offers scholarships relative to students in the Industrial and Manufacturing Engineering program. Most of the departmental scholarships are available to upper level and graduate students, including the Helgason Scholarship. Incoming students must apply for general academic or financial scholarships through the Financial Aid Department.

Wayne State University offers students scholarships through the department of Industrial and Manufacturing Engineering. Students must write an essay outlining their career goals as well as include letters of recommendation from faculty and a professional resume. Applicants being considered for the awards may also be subject to an interview.

A few of the nearly dozen scholarships sponsored by the College of Manufacturing Engineering at the University of Wisconsin-Stout are:

Rath Foundation Scholarships are awarded to new or transfer students who are at the top of their class academically. Up to $6,000 possible.
An upper level manufacturing engineering student with an internship already under his or her belt may qualify for the John Entorf Scholarship. Awards are up to $2,000.
3M Wisconsin Community Affairs Council Scholarships are specifically designed for students in at least their junior year of the ME program. Awards are $1,000.
Minority Scholarships

Traditionally minority students have been underrepresented in the sciences and engineering fields. For this reason minority students, including women, will find an almost endless array of scholarships all designed to offer the best support possible: money.

The Society of Women Engineers (SWE) annually awards well over 100 scholarships to female students pursuing degrees in an accredited engineering program. Applicants may be undergraduate or graduate students.

The National Society of Black Engineers (NSBE) offers dozens of scholarships funded by generous corporate sponsors like ExxonMobil, Delta Airlines and Northrop Grumman. In most cases applicants must demonstrate above average academic talents in the major.

The American Indian Science and Engineering Society sponsors scholarships for students majoring in an array of engineering degrees, including manufacturing engineering. Applicants must be ready to offer a Certificate of Indian Blood along with other specified criteria.

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American Society of Civil Engineers

The American Society of Civil Engineers (ASCE) is a professional body founded in 1852 to represent members of the civil engineering profession worldwide. It is the oldest national engineering society in the United States. ASCE’s vision is to have engineers positioned as global leaders who strive toward building a better quality of life. Its world headquarters is in Reston, Virginia.

ASCE was founded in New York City on November 5, 1852 when twelve engineers met at the offices of the Croton Aqueduct and formed the American Society of Civil Engineers and Architects. ASCE was the first national engineering society created in the United States.

As part of understanding the history of civil engineering and promoting the civil engineering profession, a survey of the historic accomplishments of civil engineers is continually conducted by ASCE members. Such reviews of civil engineering accomplishments have produced various lists of the notable categories and projects of the profession.

The society canvassed its members in 1999 to identify the 10 civil engineering achievements that had the greatest positive impact on life in the 20th century. They chose to recognize broad categories of achievements rather than individual projects:

* Airport design and development, as exemplified by the Kansai International Airport
* Dams, as exemplified by Hoover Dam
* The Interstate highway system
* Long-span bridges, as exemplified by the Golden Gate Bridge
* Rail transportation, as exemplified by the Eurotunnel rail system
* Sanitary landfills and solid waste disposal
* Skyscrapers, as exemplified by the Empire State Building
* Wastewater treatment, as exemplified by the Chicago wastewater system
* Water supply and distribution, as exemplified by the California State Water Project, the subject of California Water Wars
* Water transportation, as exemplified by the Panama Canal

ASCE encourages its affiliates to support state and local public and governmental affairs activities, especially through efforts by its grassroots Key Contact program. The Society’s federal priority issues for the 110th Congress are clean water, drinking water and wastewater, math and science education, natural hazards mitigation and infrastructure security, Qualifications Based Selection for engineering services, smart growth/sustainable development and transportation infrastructure. The state priority issues are infrastructure issues, licensing, math and science education, procurement of professional services, smart growth, and transportation infrastructure.

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Downwell Demolition wins Recycling Contract of the Year award

For the CRA’s first annual award scheme, submissions were invited in a variety of categories with the Recycling Contract of the Year being one of the most fiercely contested.

Downwell Demolition has won the Construction Recycling Alliance’s (CRA) prestigious ‘Recycling Contract of the Year’ award. The company’s impressive recycling performance whilst demolishing at number of structures at the famous Leavesden film studios formed the basis of its successful entry.

Downwell Demolition’s successful entry focused solely on its six month contract at Warner Brothers’ Leavesden Studios in Hertfordshire. The project entailed stripping-out and dismantling the world-famous studio buildings where the entire series of Harry Potter films together with the James Bond film Goldeneye were produced. A total of seven stage set buildings were stripped of their ceilings, roofs and existing sound-proofing to allow the creation of new structures that can be used to produce forthcoming blockbuster movies.

Downwell Demolition was able to demonstrate high levels of reuse and recycling whilst carrying out the various activities during the project, which included dismantling the scaffold framework housed in the high ceilings of the film sets, thus allowing it to be reused elsewhere on site. The company also successfully completed the crushing, screening and stockpiling of 20,000m3 of concrete rubble on-site so as to allow the material to be reused during the facility’s redevelopment. Other material such as wood, scrap metal and plastics were segregated and recycled at dedicated facilities thus ensuring a recycling rate in excess of 97%.

Commenting on Downwell Demolition’s success company director Matt Philips remarked, “I am really pleased to accept this prestigious award on behalf of all the entire Downwell team. The Leavesden project was challenging in many respects and our team of operatives and labourers not only worked hard on completing what was asked of them on time and on budget but also excelled at reusing and recycling waste materials arising from the work. The award also acknowledges Downwell Demolition’s on-going investment in recycling equipment with our latest machine, a Scavik jaw crusher, used to good effect throughout the project.

Director of the CRA, David Barnes, summarised Downwell Demolition’s success, “Downwell is one of the demolition industry’s up and coming companies, so it was reassuring to see their commitment and determination in reusing and recycling as much of the material on site as possible. The company fought off some strong competition to win this award and they should be justifiably proud of their success”.

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TWI awarded major contract

A major framework contract to support the fabrication of key components of the ITER nuclear fusion reactor was awarded to TWI by Fusion for Energy (F4E), the organisation delivering the European contribution to the ground-breaking ITER International Fusion Energy project. ITER is a first-of-a-kind global collaboration. It will be the world's largest experimental fusion facility and is designed to demonstrate the scientific and technological feasibility of fusion power.

The four-year contract will see TWI (with subcontractors Ceram and The Test House) provide engineering support to F4E on the performance of materials, joining, structural integrity of joints and non-destructive testing activities in support of the manufacture of components such as the vacuum vessel, magnets system, remote handling equipment and in-vessel parts. The core of ITER is the ‘Tokamak’ based doughnut-shaped vacuum vessel in which plasma is heated and confined in magnetic fields, as no solid material could withstand the extremely high temperature of the plasma necessary for fusion to occur at around 150 million degrees Centigrade.

The construction of ITER, underway at Cadarache southern France, is the next exciting phase of an international fusion development programme to meet the world’s demand for clean and sustainable energy. It builds on the knowledge gathered from various global fusion energy projects including the Joint European Torus (JET) fusion reactor in Oxfordshire UK, where, almost thirty years ago, the first plasma was achieved by fusing light atoms.

Calling upon all of TWI’s technical specialisms and encompassing many metallic and composite materials, the support TWI will provide to F4E will include: engineering and materials studies; assessment and testing of joining technologies including destructive and non-destructive testing; specification of design and manufacturing procedures; failure analysis; technical audits; and ensuring appropriate certification, validation and qualification of all procedures and personnel involved in the build of components for the reactor.

TWI Chief Executive Christoph Wiesner commented, ‘TWI has supported fusion projects for over 30 years as the science has developed from concept into reality. The award of this contract by F4E recognises TWI’s unique expertise and independence in all aspects of materials joining technology, which are critical for the design and fabrication of the reactor components and ultimately to the success of the ITER project. TWI is very proud to play its part in this project which has a vital role in the world’s drive to secure sustainable, low carbon forms of power generation.’

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Boss Cabin’s Big Space Heated by Webasto

In order to provide diesel powered interior heating for their new “Big Space” towable welfare cabin, world-leading manufacturer of automotive, CV and marine heating, cooling and ventilation systems specialist Webasto has been selected by Boss Cabins.

Big Space maintains the company’s hybrid interior power technology by combining a special Eco Assist power pack, which silently provides power and light, with an advanced Webasto Air Top 2000 ST diesel-powered interior heating system. “Big Space” only needs occasional generator usage to top up the power pack’s integral bank of batteries.

Boss Cabins chose the Air Top blown air interior heater because of its high performance, light weight and compact dimensions, which frees up valuable storage space. Air Top also features easy installation and inexpensive maintenance & servicing, thanks to stepless control, efficient combustion and low diesel consumption, providing comfortable warmth at the touch of a button.

“Big Space” got a warm reception at the recent Executive Hire Show in Coventry: The new cabin includes toilet facilities and enables up to 10 people to wash, relax and prepare meals in comfort, but importantly also includes an office for use as a site control area.

Graham Stansfield is Boss Cabin’s Managing Director and is impressed with the Webasto heater’s performance saying: “Webasto has produced a simple to operate, well proven product which we’re confident will stand the test of time - many site personnel have little formal training, so it is important that the systems we specify are both robust and uncomplicated. Choosing to work with Webasto was a straight forward decision because my colleagues and I admired their pro-active approach, along with their keenness to work with a young business. We’ve now built a very good working relationship but are still pleasantly surprised by Webasto’s willingness to “go that extra mile” when circumstances need more input from them than usual.”

Boss Cabins has just celebrated its second year in business in May 2012. The company was formed by a small group of like-minded professionals who have already brought a high degree of experience, skills and enthusiasm to the market. Based in Grantham, Lincolnshire, the company’s main customers are councils, utility providers and rental companies throughout England, Scotland, Wales and Ireland.

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Siltbuster will present its "Big pHil" at UK Concrete Show

Siltbuster Limited is soon revealing ‘Big pHil’, the latest in its range of Concrete Washout Solutions at the UK Concrete Show at Coventry’s Ricoh Arena on 22nd February.

A larger and more versatile version of Siltbuster’s groundbreaking RCW (Roadside Concrete Washout) unit, ‘Big pHil’ provides on-site capture, treatment and neutralisation of high pH cement laden washwater runoff from a wide range of concreting plant equipment, including crane skips up to 2,000 litre capacity, concrete pumps and the like.

This newly developed, fully integrated system, is built on a 6m long transportable hooklift platform and is the latest in the range of innovative and popular carbon dioxide (CO2) pH adjustment systems from Siltbuster but with the added benefit of providing washwater recycling to further reduce the need to discharge water off-site.

Like Siltbuster’s other pH adjustment systems, the use of clever chemistry is at the centre of Big pHil’s treatment process which also includes:

· Receiving and segregating waste concrete from the dirty washwater;

· Treating the washwater to remove the gross suspended solids;

· Automatically reducing the pH of the washwater;

· Settlement of any solids precipitated from the cement laden water;

· Storing the treated water;

· Reusing the re-circulated water for further washing down (using the onboard treated water pump and high pressure hose line).


The system provides automated carbon dioxide pH adjustment of the washwater, adjusting its pH level from highly alkaline (circa. pH 13) to neutral (circa. pH 6 - 8) within the limits set by the Environment Agency.

Compared to using strong acids, carbon dioxide reduction of high pH water is intrinsically safe, as it is virtually impossible to lower the pH below 6, the lower consent level set by the Environment Agency. From a convenience point of view, bottled CO2 is readily available from numerous industrial gas suppliers across the country, with unused or partially spent carbon dioxide cylinders able to be returned to the supplier.

Reducing the pH of wash water using Siltbuster’s proven carbon dioxide dosing system is not only intrinsically safe for the environment, but also for the operator washing down plant. Strong acids do not need to be handled or stored on site and clean, treated and neutral pH water is used for washing, thereby avoiding the risk of the operator suffering chemical burns normally associated with concrete washwater.

With the low level reception area readily approachable from three sides of the unit, opening tailgate, drop down sides and large reception area, Big pHil offers real flexibility on site making it ideally suited for inner city with tower crane concrete skips, as well as larger scale projects and concrete pours. Access to the handrailed platform area on top of the treatment unit provides the operator with an elevated platform from which to wash the top and inside of the plant in a controlled secure area.

“Feedback from contractors about RCW units for concrete mixer truck chute washout has been great, but it is clear that other, often larger, concreting plant need the same treatment. It became apparent that a larger unit was called for and coupled with the issue, late last year, of the Environment Agency’s regulatory position statement on concrete washwaters on construction sites, Big pHil was born”, says Richard Coulton, Siltbuster’s managing director.

“We’re pleased to continue to help the construction industry meet their regulatory requirements and support the UK Concrete Show so we’re delighted to be revealing Big pHil at the show and look forward to wetting the big baby’s head across the UK!”

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Fibre Reinforced Concrete

Conventional concrete containing discontinuous discrete fibres is called fibre-reinforced concrete. Fibers of various shape and size produced from steel, plastic, glass, carbon and natural materials have been used.
However for any reinforcement to be effective, it must be stiffer than the concrete matrix that is reinforcing. Generally the less stiff fibres (made from plastic and natural materials) only offer benefits in improving the tensile strength of plastic and semi-hardened concrete and are therefore mainly used to reduce plastic shrinkage and plastic settlement cracking. The stiffer fibres improve both the tensile strength and the toughness of harden concrete.

The most widely used stiff fibre is steel. Low volume fractions of fibres (less than 1%) are used to reduce shrinkage cracking. Moderate volume fractions (between 1% to 2%) increase flexural strength, fracture toughness and impact resistance. High volume fractions (greater than 2%) lead to strain hardening of the composites. The shape and length of the fibres also play a role in the fibres’ effectiveness in improving the properties of the concrete. The use of fibres in concrete can have a marked effect on the workability of the concrete and this need to be taken into account in the mix proportion of fibre-reinforced concrete.

Currently a great deal of research is being undertaken into the use of ultra-high-performance fibre-reinforced composites. One of the benefits of these materials is extremely high ductility. Fibre-reinforced concrete has been used for precast panels, airfield and highway pavements, industrial floors and in spraying concrete for slope stability and underground mining applications.

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Concrete Countertops for your Home

The biggest reason you could have to choose concrete countertops over any other kind would be to take advantage of the inexpensive nature of the material. Nothing could be simpler and more readily available than poured concrete. Of course, no one likes the drab gray of plain concrete. Anyone who wants something more colorful can easily use staining – a method that is both cheap and simple.

The great thing about deciding to use a concrete for a countertop is that the material does lend itself well to DIY projects – even by novices who have little experience with it. Any investment you put into concrete is repaid well too – there’s quite nothing like concrete even among materials that last. Even used in places where it is exposed to the elements, concrete tends to last for at least a half-century once properly laid.

So concrete is cheap, durable and easy to work with. Isn’t there anything that works against it as a material of choice to use on countertops? Well, you could consider the cost of the sealing material that you need to use on top of laid concrete that would actually make it suitable for use as a countertop. Since countertops need to be buttery smooth in a way concrete just isn’t, you really need to consider finishing a countertop after you’ve laid it. The sealer makes the surface smooth enough and stain-proofed enough, for everyday use. If you don’t feel that you’re up to the task of building a concrete countertop yourself, having a professional come in and do it for you can turn out to be a somewhat expensive service to buy too.

If you do take the plunge and decide to get your feet wet, learning how to put down a concrete slab yourself, if you aren’t careful, you might find yourself in in a little too deep. Wrongly done, concrete can cure unevenly and developed cracks. And concrete countertops, even if you do succeed in installing them properly, do present quite a challenge when you need to to install a sink or something. The material is one of the hardest known to man, and cutting an even opening without damaging everything can be a serious problem. You also need to consider how concrete ages. While the structural integrity of the material can be untouchable for centuries, the glossy sealer overlay can have a finite life.

Concrete happens to be a material that’s easy to achieve mediocre results with, and difficult to finish with perfection. If you can afford to call in a professional, or if you can afford to take the time to learn really well how it is done in the DIY method, it could be the right material for your home.

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Specification for Placing of Concrete

Concrete shall be deposited as nearly as possible to its final position and shall be placed in layers not more than 30 cm thick. Concrete shall be placed at such a rate that it is at all times plastic and will flow readily around reinforcement and embedded parts. Once placing is started, it shall be a continuous operation until the lift is completed. The area of placement shall not be more than that which can be completed in one pour in compliance with this specification.

The time between placing of successive layers forming a lift shall be short enough to permit a vibrator to penetrate the lower layer while the upper layer is being compacted. The minimum time between completion of a lift and the commencement of placing of a succeeding lift shall be 72 hours.

Pneumatic placing and pumping of concrete may only be used with the approval of client. In such a case, discharge lines shall be horizontal or inclined upwards. The discharge end shall not be more than 3m from the point of placement and shall supply a continuous stream of concrete without air pockets. Aluminum piping shall not be used.

During hot weather, special precautions, as directed or approved by the owner, shall be taken to ensure that the temperature of the concrete when it is placed does not exceed 30 degrees Centigrade. These may include, but shall not be limited to, the use of chilled mixing water, cooling of aggregate or working at night.

Concrete shall not be placed in exposed areas during rain and, should it rain while placing is in progress, the placed concrete shall be covered with vinyl or other impervious sheets. Placing may be resumed only when rain stops well before initial set of the placed concrete occurs. Otherwise, placing operations shall cease and the boundaries of the pour shall be prepared as specified for construction joints.

Concrete shall not be placed under water except when specifically directed and authorized in writing by the owner. In such a case, placing shall be done from a bottom?discharging watertight bucket or by termite pipe penetrating the previously placed concrete so that fresh concrete is always deposited below the surface and the operation is continuous until completion of the pour.

Compaction

Concrete shall be compacted by mechanical vibrators electrically or pneumatically driven. Immersion vibrators shall operate, when fully immersed, at speeds of not less than 7,000 impulses per minute for vibrating heads of less than 10 cm diameter and 6,000 impulses per minute for heads 10 cm or greater in diameter. They shall be slowly immersed and withdrawn vertically at spacing of 30 cm to 50 cm, with vibration periods of 10 to 15 seconds for each penetration, and shall penetrate into the layer below. Vibrators shall not come into contact with reinforcement or embedded parts.

Where immersion vibrators cannot be used, the concrete shall be compacted by form vibrators, rigidly attached to the outside of the form, operating at not less than 8,000 impulses per minute.

Curing

Concrete surfaces shall be kept continuously moist for at least 14 days after placing and until the concrete temperature produced by heat of hydration of the cement has peaked and fallen at least 10 centigrade degrees. Initial curing of exposed surfaces shall be performed by atomized water spray positioned so that all surfaces to be cured are constantly moist, or by a continuous layer of burlap kept constantly wet. Hand sprinkling shall not be used except in conjunction with the burlap alternative.

Forms capable of moisture loss, such as plywood forms, shall be regularly sprinkled with water to avoid loss of moisture from formed surfaces of the concrete.

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Solutions for Swimming Pools

Outdoor Swimming Pools
Two basic alternatives are available for outdoor swimming pools: in-ground pools and above-ground pools. In-ground pools are set into the ground, thus requiring ground excavation. Only solutions for in-ground pools are presented here.
Main Components of in-ground Swimming Pools
The main components are:
Structure: floor / foundation; walls
Waterproofing element
Decorative finishing
Equipment and accessories
The structure itself is usually not sufficiently watertight, and therefore a waterproofing element is needed. In case of a conventionally built structure, this waterproofing element consists of a cementitious coating. It serves at the same time as a substrate for the decorative finish which is made up of ceramic tiles (or mosaic) or a decorative coating. Sheet membranes offer an alternative solution, combining the waterproofing and finishing function in a single element.
“Membranes”, consisting of thicker and more robust sheets, are installed in the traditional way, by cutting and seam welding on site. By contrast, “liners”, consisting of thinner sheets, are completely prefabricated to the size of each pool and then installed simply by attaching them onto profiles on the pool edge. They can also be easily replaced at the end of their service life.
Design Swimming Pools
Swimming pools must be designed by specialists in accordance with the state of the art, as well as standards and regulations in force.
Requirements for Swimming Pools
Esthetic Requirements
Free pool geometry
Wide choice of esthetic design possibilities (colours and patterns of pool surface)
Colour stability
Economical Requirements
Favorable investment cost
Ease of cleaning
Easy and cost-effective renewal possibilities
Durability Requirements
Mechanical (impact) resistance
Resistance to substrate cracking and movement
Frost resistance
Resistance to (chlorine; ozone) treated water
Resistance to sun cream
Resistance to algae and mold growth

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Testing Concrete Aggregates

Here after is the specification for concrete aggregate testing in a hi-rise building construction.

General

Samples of the fine and coarse aggregates approved by the Engineer shall be kept on the Site and shall give a fair indication of the approved quality of the aggregate for comparison with the aggregate delivered during the course of the works.

Should a sample fail to comply with any of tests, the Engineer may at his own discretion reject the batch from which sample was taken, or order it to be washed and/or screened, or permit such to be used with variations in the proportions of the concrete mixes specified, all a the Contractor’s expense. Any batch of aggregate rejected by the Engineer shall be removed from the site forthwith and replaced entirely at the Contractor’s expense.

All sample and testing of aggregates shall be carried out in accordance with ASTM C33.

Preliminary Aggregate Tests

As soon as the source of supply of aggregate have been approved, the Contractor shall instruct the testing agency to carry out the following tests for compliance with “Specification of Concrete Aggregates” (ASTM C33).

Sieve analysis
Tests for clay, silt and dust content
Tests for organic impurities
Tests for salt content (chloride and sulfate ions)
The results of these tests shall be submitted for approval as soon as available. Test (1) and (2) with tests for the moisture content of each aggregate shall be carried out on the sample used for each trial mix.

Testing sampling of Aggregates

The contractors shall carry out such tests on aggregate samples as are necessary for the production of the specified concrete. The minimum incremental frequency of tests on each type of concrete used for the works shall be:

Sieve analysis: at least once weekly
Moisture content: at least once weekly
Tests for clay, silt and dust content: at least once fortnightlu
Tests for organic impurities: at least once monthly
Tests for salt content (chloride and sulfate ions): for every 500 cubic meters of concrete placed.
If for any reason the Engineer is not satisfied with the works concrete, he may instruct the Contractor to further increase the rate of sampling. Conversely, the rate of sampling may be reduce by the Engineer when consistent high quality been well established.

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Hydropower financing:current trends and key issues

In the late 2000s the power sector in many countries experienced a major revolution. The old vertically-integrated, nationally owned power utilities were unbundled and the concept of freestanding independent power generating companies (IPPs) was established. This trend was part of a wider process of encouraging more private participation in the ownership and development of infrastructure, including hydropower and multi-purpose water projects. With this arrangement most projects were developed using the BOOT model (build-own-operate-transfer) under which a special purpose private company finances the scheme (usually on a non-recourse basis) and assumes virtually all of the project risks. In return it owns the infrastructure for the duration of the concession.
While this formula worked well for the thermal power sector, it quickly became apparent that the situation is more complicated when it comes to major water resources projects. In general the experience with projects such as large hydropower schemes has not been favourable, with many MOUs being signed between governments and prospective private developers, but few schemes actually reaching the construction stage. In many cases the main problem has been an inability to finance the project.
A number of Case Studies have been undertaken by the author. Although each is different, it is possible to detect certain overriding issues which dominate the private financing scene. They are:
1. RISKS dominate the availability and cost of finance, and are tending to migrate back to the public sector.
2. TARIFFS tend to be higher (than the public sector alternative) due to high soft costs, the layering of risk, and heavy debt service obligations.
3. FINANCIAL viability tends to compete with wider economic considerations, and it can distort the optimisation.
4. The PUBLIC SECTOR has yet to find a workable model for attracting private participation.
Faced with these problems, there is an increasing tendency to move towards something that is often referred to as a “Pubic-Private Partnership” – although this term has no clear definition and can mean different things to different people. The objective is to move towards come half-way project structure that preserves the best of both the traditional public sector model and the perceived benefits of private sector participation through a BOOT type of arrangement.
The structuring of a project (in terms of ownership, risk sharing, etc.) is often dominated by financing considerations. There is no single generic solution that can be applied to all projects, but the paper will discuss some of the key issues that arise in selecting the most appropriate financing model for a particular project.

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Broadcast Flooring

Scope of work for broadcast flooring
The specified system of broadcast flooring shall provide a wearing surface with waterproofing properties.
The system is based on a solvent free epoxy, which has a good resistance to wear and chemicals.
Advantages of broadcast epoxy flooring
Good impact resistance
Skid-resistant finish
Good chemical resistance
Suitable for wet process area
High wear and abrasion resistance
System build-up for broadcast system
1.If needed, moisture barrier (if > 4% pbw moisture content into the substrate)
Epocem Primer ( Primer coat) 1 x Epocem Primer Approximately 0.15 Kg/m²
Moisture barrier (Body coat) 1 x Sikafloor 81 Epocem (2 mm minimum): 2.1 kg/m²/mm
2. Primer + levelling broadcast course
Wearing course 1 mm (Levelling layer) Sikafloor 161+ Silica Flour :Approx. 1,2 Kg/m²/mm + 0.3 Kg/m²/mm
Broadcast onto fresh resin (Broadcast) Quartz sand from 0.3 – 0.8 mm or 0.6 – 1.2 mm 4 – 5 kg/m²
Sealing coat (Coloured coat) Sikafloor 264 0.7 kg/m² (minimum)
(Approx. system thickness from 3 mm, without moisture barrier)
Application of broadcast epoxy flooring system
Primer and leveling broadcasted course: Apply Sikafloor 161 and Silica Flour on a 1 mm thickness.
Broadcast the surface of the resin to excess to achieve the desired degree of slip resistance. Next day remove all excess by brush and vacuum.
Sealing coat: Apply a sealing coat of Sikafloor264 by roller or squeegee.
[NB. Certain colors may require a slightly increased consumption applied in two coats].

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Using Solar Energy for your Home Power

What we get from the sun? Heat and light as we all see. Another saying is sun’s energy or solar energy. The power from the sun is the most abundant form of energy available on earth. The sun has been one of the biggest factors dictating every living being’s stay on the earth. If we go the right path, we can harness more from the solar energy, like generating home power for daily use.
Advantages of home power taken from Solar Energy
The solar energy solution is gaining popularity amongst the alternate energy solutions.
• Green energy solution: When you look at the solar energy solution, you will realize that it uses absolutely no fuel other than the sun’s light. Moreover, it does not release into the atmosphere anything harmful.
• Cheapest power solution: First, the energy comes free. Then, the installation cost is a one-time cost. Finally, the investment is recovered within a few years of installation, making the power generated by solar energy absolutely free.
• Convenience of storage: You cannot store conventional power but you can store solar power for future use. The sun’s energy comes to rescue even in the times of darkness! Storing it also ensures a 24×7 supply of power, thus saving you from any power outage.
• Low on maintenance: The solar energy systems are easy to maintain. They do not involve high costs or too much effort, thus letting you reap the benefits of the solution comfortably.
How can solar energy be used for home power?
Solar power can be used as home power in our everyday lives by adopting the following solar power systems:
• Solar cooking system: Solar cooking is about cooking without lighting a fire or using electricity! Before you wonder, let me tell you that solar cooking is not about bland food. You can cook in more ways than one – boil, roast, or bake, cook the way you want! The only demand that solar cooking makes of you is being patient; it is a matter of more than a few minutes. However, it is not asking for too much given that you will get tasteful and healthy food without worrying about paying your gas or electricity bill.
• Solar lighting system: You can now light up the entire house, use every electrical appliance without thinking about cutting down bills. The solar lighting system lights up your house even in the nights, thanks to the power storage feature it has.
• Solar heating system: You can keep your house cozy and warm using the solar heating system without worrying about costs.
You can make your own home power system energy to eliminate your power bill. Make it easy by visiting

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Project Management Methodology

Projects are usually split into phases often along the lines of initiation, control and closure. During each phase a number of documents are produced as part of the project control process.

Initiating a Project

All projects start with an idea for a product, service, new capability or other desired outcome. The idea is communicated to the project sponsor using the mandate. The mandate provides a structured approach to proposing a project and contains the project’s business case.

Once the mandate has been approved a further document is prepared that explains the project in greater detail. The project definition report is used to provide this information. This document is used as a key part of the assessment when deciding whether the project should be undertaken.

In particular it outlines the goals, objectives, scope, deliverables, assumptions, constraints, risks, issues, key people, benefits, costs and duration.

If authorisation to proceed is given, the contract is used to obtain formal agreement from the project sponsor and budget holder to start the project. This signifies the end of the initiation phase.

Controlling a Project

The control phase involves managing and tracking the project. To do this a project plan is developed. The project plan is most commonly expressed in the form of a Gantt chart and identifies the stages, tasks, timeline and resources. A good plan will include regular milestones that act as a measure of progress and keep the project team focused on short-term goals. Project plans may also include information about costs and dependent projects. A tracking Gantt chart can be used to monitor progress.

Once you have planned the project it is important to identify any factors that could have an impact on it. This is done using the issues log and risk log. The issues log is used to record issues and a plan to address them. The risk log is used to record and grade risks with an associated action plan to mitigate them. Often confused, risks and issues are defined as follows:

Risk: The likelihood of the occurrence of an event, usually a negative one that may adversely affect the successful completion of a project.

Issue: A concern raised by any stakeholder that needs to be addressed, either immediately or during a project.

Key to good project management and a successful project outcome is effective communication. The progress report is used to communicate progress on a regular basis, typically weekly or monthly, to all stakeholders of the project.

The control phase ends once the project has achieved its goals and objectives as detailed in the project definition report. A project may be stopped prior to completion for a variety of reasons, including changes within a business, lack of resources or higher priorities.

Closing a Project

Project closure is an important aspect of project management that is often overlooked. A project that is not closed will continue to consume resources, albeit slowly.

To receive acknowledgment from the customer that the project has ended the customer acceptance form is used. Once signed off the project team is disbanded and no more work is carried out.

At this point it is important to know whether the project has achieved its goals and objectives. This is done using the project closure report. This document communicates how well the project has performed against its original business case, quality criteria, costs, duration and tolerances.

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Testing of Concrete Blocks

NTRODUCTION
Concrete can be converted into precast masonry units such as Hollow and Solid normal and light weight concrete blocks of suitable size to be used for load and non-load bearing units for wallings. Use of such concrete blocks are more appropriate in region where soil bricks are costly, poor in strength and are not available. Depending upon the structural requirements of masonry unit, concrete mixes can be designed using ingredients available locally or if not found suitable then with in the most economical distance. The concrete mix used for normal hollow and solid blocks shall not be richer than one part by volume of cement to 6 parts by volume of combined room dry aggregates before mixing. Hollow concrete blocks for normal work used in masonry when reinforced is used shall not be leaner than 1 part cement to 8 parts room dry sand by volume. The mixes are designed with the available materials to give overall economy and the required properties of the products. The hollow load bearing concrete blocks of the standard size 400 x 200 x 200 mm will weight between 17 and 26 kg (1063 to 1625 kg/m3) when made with normal weight aggregates. Normal weight blocks are made with cement, sand, gravel, crushed stone and air-cooled slag. The grading for sand used in Hollow concrete block shall be as given below:

I.S. Sieve Size

Percentage Passing

4.75 mm

98-100

2.36 mm

80-100

1.18 mm

60-80

600 Micron

40-65

300 Micron

10-40

150 Micron

0-10

The aggregates for solid blocks shall be sand as per IS : 383-1970 and well graded aggregate of suitable maximum size as per the dimensions of the block. The mixes are properly designed as per standard practice. Concrete admixtures may be used in both Hollow and Solid concrete blocks.

SPECIMENS
20 full size units shall be measured for length, width and height. Cored units shall also be measured for minimum thickness of face, shells and webs. From these 3 blocks are to be tested for block density, 8 blocks for compressive strength, 3 blocks for water absorption and 3 blocks for drying shrinkage and moisture movement.

DETERMINATION OF BLOCK DENSITY
Three blocks shall be dried to constant mass in a suitable oven heated to approximately 1000C. After cooling the blocks to room temperature, the dimensions of each block shall be measured in centimeters to the nearest millimeter and the overall volume computed in cubic centimeters. The blocks shall then be weighted in kilograms to the nearest 10 gm. The density of each block calculated as follows:

Density in kg/m3 = Mass of block in kg/Mass of block in cm2 * 106

DETERMINATION OF WATER ABSORPTION
Three full size blocks shall be completely immersed in clean water at room temperature for 24 hours. The blocks shall then be removed from the water and allowed to drain for one minute by placing them on a 10 mm or coarser wire mesh, visible surface water being removed with a damp cloth, the saturated and surface dry blocks immediately weighed. After weighing all blocks shall be dried in a ventilated oven at 100 to 1150C for not less than 24 hours and until two successive weighing at intervals of 2 hours show an increment of loss not greater than 0.2 percent of the last previously determined mass of the specimen. The water absorption calculates as given below:
Absorption, percent =(A-B)/B * 100

Where,
A = wet mass of unit in kg.
B = dry mass of unit in kg.

TESTING BLOCKS FOR COMPRESSIVE STRENGTH
COMPRESSIN TESTING MACHINE (CTM)
The compression testing machine should be as per IS : 516-1959 and I.S : 14858-2000. The load capacity, platens sizes, vertical space between platens and horizontal space between machine columns shall be as per the requirements of the specimens to be tested.

However, IS : 2185 (pert-I) – 1979 specified that when the bearing area of the steel blocks is not sufficient to cover the bearings area of the blocks, steel bearing plates shall be placed between the bearing blocks and the capped specimen after the centroid of the masonry bearing surface has been aligned with the centre of thrust of the bearing blocks. It is desirable that the bearing faces of blocks and plates used for compression testing of concrete masonry have hardness of not less than 60 (HRC).

When steel plates are employed between the steel bearing blocks and the masonry specimen, the plates shall have thickness equal to at least one-third of the distance from the edge of the bearing block to the most distant corner of the specimen. In no case shall the plate thickness be less than 12 mm.

ASTM : C 140-03 specified that when the bearing area of the upper platen or lower platen is not sufficient to cover the area of the specimen, a single steel bearing plate with a thickness equal to at least the distance from the edge of the platen to the most distant corner of the specimen shall be placed between the platen and the capped specimen. The length and width of the steel plate shall be at least 6.3 mm grater than the length and width of the unit. The surface of the platen or plate hardness shall be not less than HRC 60 (BHN 620).

Thickness of bearing plates has a significant effect on the tested compressive strength of masonry units when the bearing area of the platen is not sufficient to cover the area of the specimen. Tested compressive strength will typically increase with increased plate thickness and with reduce distance to the further corner of the specimen. Accordingly the CTM platens shall have the required dimensions with respect to the specimens to be tested on it.

TEST SPECIMENS
Eight full size units shall be tested with in 72 hours after delivery to the laboratory, during which time they shall be stored continuously in normal room air.

For the purpose of acceptance, age of testing the specimens shall be 28 days. The age shall be reckoned from the time of the addition of water to the dry ingredients.

CAPPING TEST SPECIMENS
The bearing surfaces of units shall be capped by gypsem. The gypsem and water paste shall be spread evenly on a non-absorbent surface that has been lightly coated with oil. The surface of the unit to be capped shall be brought into contact with the capping paste. The average thickness of the cap shall be not more than 3 mm. The caps shall be aged for at least 2 hours before the specimens are tested.

PROCEDURE
Specimens shall be tested with the centroid of their bearing surfaces aligned vertically with the centre of thrust of the spherically seated steel bearing blocks of the testing machine.
The load up to one-half of the expected maximum load may be applied at any convenient rate, after which the control of the machine shall be adjusted as required to give a uniform rate of travel of the moving head such that the remaining load is applied in not less than one nor more than two minutes.

The compressive strength of a concrete masonry unit shall be taken as the maximum load in Newtones divided by the gross cross sectional area of the unit in square millimeters. Report to the nearest 0.1 N/mm2 separately for each unit and the average for the 8 full units.

Note:- The Gross area is : The total area occupied by a block on its bedding face, including areas of the cavities and end recesses.

REFERENCES
1.IS : 2185 (part-I)1979 1987 1998 – Specifications for concrete masonry. Units part-I Hollow and Solid Concrete Blocks (Second Revision).
2. IS : 2185 (part-II)- 1985
Super seeding IS : 3590-1966 Specifications for concrete masonry units part-II Hollow and Solid light weight concrete blocks (First Revision)
3. IS : 2572-1963 Reaffirmed 1997 Code of practice for construction of hollow concrete block masonry.
4. IS : 383-1970 Specification for coarse and fine aggregates from natural sources for concrete (Second Revision)
5. ASTM : C 140-03 Standard test methods for sampling and testing concrete masonry units and related units.

We are thankful to Sir Kaushal Kishore for publishing his unpublished research paper here on the website. This would be of great use to all the civil engineers who work are looking for information regarding Testing of Concrete Blocks .

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Laterally Loaded Vertical Piles

When ever we are studying about a vertical pile, we need to understand that the flexural stiffness of the shaft and stiffness of the bearing soil in the upper 4D to 6D length of shaft are the two main factors on which the resistance to lateral loads of vertical pile depends.

Nondimensional solutions of Reese and Matlock help us plot the lateral-load vs. pile-head deflection relationship but the basic assumption with this is that the soil modulus K increases linearly with depth z

K= nhz
where nh coefficient of horizontal subgrade reaction.

A characteristic pile length T is given by
T=(EI/nh)1/2
where
EI= pile stiffness.


Now when a pile with free head is subjected to a lateral load Pt and moment Mt applied at the ground line, The lateral deflection y of a pile is given by

y=AyPtT3/EI+ByMtT2/EI

where
Ay and By are nondimensional coefficients.

For positive moment,
M=Am Pt T+Bm Mt

Percentage of load Transmitted To Rock Socket, Estimated by interpretation of finite-element solution for Poisson’s ratio 0.26.





Er /Ep


Er /Ep


Er /Ep



Ls /ds

0.25

1.0

4.0



0.5

54

48

44



1.0

31

23

18



1.5

17

12

8



2.0

13

8

4


Their is a negative moment imposed at the pile head either due to pile cap or another structural restraint, this can be calculated as a function of the head slope (rotation) from this equation

where
theta rad represents the counterclockwise ( + ) rotation of the pile head and Atheta and Btheta are coefficients .

This value of Mt is put in previous equations to find the influence of the degrees of fixity of the pile head.

When we have a fixed-head case, the formula becomes

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What should be the Roof slope to prevent Ponding?

As per standards, the Roof beams should have a continuous upward slope equivalent to 1/4 in/ft ( 20.8 mm/m) between a drain and the high point of a roof, in addition to minimum recommended camber to avoid ponding.

In case of insufficient slope that is less than 20.8mm/m, it should be noted that the stiffness of supporting members acting 5lb/ft2 or 239.4 N/mm2 load should not cause more than 1/2 inch or 12.7mm deflection.

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