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Roof Waterproofing By Brick Bat Coba

By
Er. Kaushal Kishore ,
Materials Engineer, Roorkee

INTRODUCTION
Waterproofing is a treatment of a surface or structure to prevent the passage of water under hydrostatic pressure. Waterproofing barrier system may be placed on the positive or negative side. Damp proofing is a treatment of a surface or structure to resit the passage of water in the absence of hydrostatic pressure. A damp proofing barrier system is used to perform the same functions as a waterproofing system but cannot be used to protect against water pressure. Water may be forced through building members by hydrostatic pressure, water vapour gradient, capillary action, wind-driven rain, or any combination of these. This movement is aggravated by porous concrete, cracks or structural defects, or joints that are improperly designed or installed. Leakage of water into structure may cause structural damage, and invariably cause damage to the contents of the structure.

New roofs RB or RCC slabs must be constructed specified by the designer. Roof waterproofing is a widely misunderstood subject. Often inadequate attention given during the construction of RB or RCC roof slab, wrong products used for waterproofing and generally insufficient treatment given, lead to leakage. Movement because of structural deflection, settlement, etc. and steep temperature variation being exposed, cause development of cracks in the roof slab and water start leaking from these cracks.

While constructing RCC roof slab, it should be borne in mind that the practice of using concrete which is not watertight and placing too much reliance on the waterproofing measures is not desirable. Concrete should be made watertight in itself and the waterproofing method should be looked upon as additional safety devices.

The grade of roof slab concrete shall be strictly as specified by the designer. The concrete materials should be properly proportioned, maintaining the specified maximum water, cement ratio, minimum cement content and required workability. The concrete should be admixed with a Superplasticiser.
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Save Environment With Green Construction

By
Er. Kaushal Kishore ,
Materials Engineer, Roorkee

NEW CEMENT
Portland cement, is made by a calcareous material, such as limestone or chalk, and from alumina and silica found as clay or shale. The process of manufacture of cement consists essentially of grinding the raw materials, mixing them intimately in certain proportions and burning in a large rotary kilin at a temperature of up to about 14500C. When the material sinters and partially fuses into balls known as clinker, the clinker is cooled and ground to a fine powder, with some gypsum added, and the resulting product is the commercial portland cement so widely used through out the world. The manufacturing of this cement release in the atmosphere 0.8 tonnes of CO2 in the production of one tonne of cement. When water is mixed with cement and aggregates in the production of concrete for use in the construction, each tonne of cement can absorb up to 0.4 tonnes of CO2 , but that still leaves an overall carbon footprint per tonne of 0.4 tonnes. In the year 2009 about 2000 million tonnes of CO2 was emitted in the atmosphere in the production of cement.

The above problems have been overcome from researches by Nikolas Vlasopoulos Chief Scientist and his colleagues at Imperial College, London, and they have set up a company of Novacem’s cement which is making cement from magnesium silicate that absorb more CO2 as it hardens. Valaspoulos responded that magnesium slicates are abundant world wide with 10,000 billion tonnes available. He is confident that material will be strong enough for use in buildings but acknowledge that getting licence to use it will take several years of testing.
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Economic Evaluation of BOT Projects

Economic Evaluation of proposed Barwah-Dhamnod Toll Road by Dr.(Mrs.)Vandana Tare (Professor, Deptt. of Civil Engg. S.G.S.I.T.S., Indore (M.P) and Er. Raj Mohammad Khan (M.E. (Civil) Transportation Engg., Indore (M.P).

ABSTRACT
Road Traffic has been growing with very rapid rate, hence the traffic intensity and volume on the road is high. The present road network is necessary to improve to accommodate the future traffic and to provide the good riding quality. The development of Infrastructure has been done by the public sector through the fund collected from taxes, but huge fund are required for modernization of road network. Due to decreasing financial resources, government is not in position to invest the funds in those developments. This has brought to focus the need of attracting private investment in road in India.

The Barwah-Dhamnod road is proposed on B.O.T. system, starts from Barwah on Indore-Khandwa Road SH-27 and passing through Mandleshwar and joining NH-3 at Dhamnod. The total length of the road is 63 Kms and road passes through the districts of Khargon and Dhar. The details of road section Barwah-Dhamnod Road under study were collected through road inventory survey. The Traffic volume survey & Willingness to pay survey were also conducted on this road. The analysis of traffic volume data was done by projection up to 15 years. The need for widening of road from single lane to two lane is justified as per the capacity of road. Based on the data collection to achieve the toll fixation rates & to estimate the concession period, a methodology is adopted which includes generation of different module. Each module calculates the required results.
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Mix Design With Superplasticizers

By
Er. Kaushal Kishore ,
Materials Engineer, Roorkee

INTRODUCTION
Superplasticizers belongs to a class of water reducer chemically different from the normal water reducers and capable of reducing water content by about 30%. The Superplasticizers are broadly classified into four groups: sulfonated melamine formaldehyde condensate (SMF), sulphonated naphthalene formaldehyde condensate (SNF), modified lignosulphonate (MLS) and others including sulphonic acid ester, polyacrylates, polystryrene sulphonates, etc. The benefits obtained by Superplasticizers in the reduction of water in the concrete mixes are best illustrated by the following examples.
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Ductal- A Stronger Concrete

What is Ductal?
Few Years back in 2006; researchers at Iowa State University have developed a new type of concrete that is much stronger than conventional concrete. It can withstand pressures up to 595,000 pounds — more than the weight of seven semi trucks.

A new kind of concrete called Ductal that might allow bridges to hold more weight and last longer. Although it is 10 times more expensive than traditional materials but stronger and virtually impermeable, helping bridges become more durable.

The researchers conducted a load-bearing capacity test using a 71-foot beam made out the new concrete. They applied increasing amounts of hydraulic pressure to the top of the beam to see how much it could withstand before breaking. It finally broke with a loud pop at 595,000 pounds. The ultra-high performance concrete is made from sand, cement, water and small steel fibers. Standard concrete uses coarser materials. The new concrete is specifically engineered to include finer materials and steel fibers, making it denser and stronger.

We are extremely thankful to Dr. Varenyam Achal for sharing  this research on our site and thus helping civil engineering students.