Infrastructure

Cement

The main cement materials are C3S, C2S(75%), C3A(3-10%) and C4AF (1-15%) and the main materials of Cement are Limestone(90%), Coal Ash, Bauxite and Iron ore(10%).

In order to assess the quality of Cement it is necessary to evaluate it Chemically and Physically before using it in any structure. Standard Specifications have adopted certain fixed values of all properties of Cement based on experience and requirement in practice. Any deviations from such standards indicate the presence of inferior materials used during the process of its manufacture.

All the required parameters are necessary to get tested for Cement since they all are interrelated as shown below:- An excessive amount of SO3, MgO or Free lime will may cause the Soundness and the Unsoundness of Cement may case the expansion of cement.

Better will be the fineness, more rapid will be the Heat of Hydration as more surface area will come in contact with water.

High quantity of Alumina and Iron Oxide causes rapid Initial setting of Cement. Gypsum addition is required at the time of clinker formation to control the setting of cements. The loss on ignition (LOI) shows the extent of Pre Hydration and carbonation due to exposure to atmosphere and moist environment.

Higher IR indicates the presence of Argillaceous and Siliceous Contamination or Adulteration.

Aggregates

Aggregates occupy nearly 70-75% of the total Valium of concrete. Physical, chemical and thermal properties of aggregates substantially influence the properties of concrete. They impart greater volume of stability add durability to the concrete. Selection of aggregates must be based on the knowledge of properties determined by laboratory tests, Petrography examinations etc.

Particle shape:-

Well-rounded particles required less water and less past for a given workability in contrary to the Elongated and Flaky prattles.

Grading:-

The maximum size of aggregate Governs the strength and workability of concrete through their surface area which is to be coated with cement paste. For leaner mixes, larger maximum size of aggregate gives better results. For mixes of higher CS, smaller maximum size of aggregate is preferable.

Crushing strength:-

Aggregates required to be strong. It is important from the point of view of stability in the mixer and also for better resistance to abrasion or attrition during service life of concrete.

Abrasion resistance:-

It is an important test for the concrete exposed to wearing action.

Deleterious Materials:-

Clay lumps, Mica, Coal, shale, Soft fragments, Iron pyrites all are deleterious materials and are necessary to be limited to 1% only as these effect the CS of concrete. For every1% of these in the fine aggregate, the CS can decrease by 5%.

Soundness:-

Used in the aggregates liable to be exposed to action of Frost.

Alkali-aggregate Reactivity:-

When this is on higher side, the product of the alkali-silica reaction is an alkali-silicate get which causes the expansion in the concrete leading to the cracks in the structures and bulging of concrete.

Concrete:-

Concrete is widely used as a material of Construction because of the ease with which it can be put to the desired shape when in the fresh state and can have the desire properties like Workability, Strength and Durability, when hardened.

Deteriorating Agencies for Concrete:-

Sulfates, Chlorides, Carbonates Water, Temperature

Sulfate and Chlorides:-

Causes Corrosion of Steel

Water:-

Causes delaying setting time and reduces the Strength

Carbonates:-

Lowers pH value and reduces Protection to steel reinforcement, Causes Abrasion, Attrition or Cavitations

Temperature:-

Causes normal Cracking

Admixtures-

Admixtures are generally used in concrete to modify the properties of concrete in the plastic or hardened state. Whenever admixtures are decided to be used for a project, it is necessary to evaluate the mixture for specific use with the concrete-making materials and mix proportions to be used for the work.

Admixtures help on lowering the Water content in the mix, there by helping in lowering the water / Cement Ratio and contributing in enhancement of durability of concrete.

Admixtures when added to concrete, mortar or grout, increase the rate of Hydration of Hydraulic Cement, soften the time of set and increase the rate of hardening or strength.

Admixtures also provide homogeneity and cohesiveness and a reduced tendency to bleed.

Wood

Timber is one of the valuable and versatile raw material put to a variety of different uses depending upon its structure and properties. SRI assists the industry by ensuring the quality of the timber through its quality control checking.

Parameters Tested For Wood

Timber Species that can be identified by us on Declaration

Specialized Studies / Projects

Instrumentation