Slab on grade is a slab directly supported on the soil. Slab on grade is used for construction of industrial floor and rigid pavement. For construction of slab on grade, fibers mainly steel fibers are used with specified doses. Addition of the fiber in the slab on grade improved the ductility and post cracking nature of the load verses deflection curve. Area under load deflection curve is called toughness. Peak load of SFRC is higher than the plain cement concrete. Steel fibers are more appropriate to used in slab on grade that synthetic and polypropylene fiber. Non linear fracture mechanics of concrete between cracks is evaluated to understand the performance of the SFRC. Parametric study carried out to evaluate the effect of type of steel fiber, dose of steel fiber and load -deflection curve on the depth of the slab on grade. Some equations and charts are proposed for the calculation of dose of fibers based on loading criteria and minimum depth of slab on grade. Plastic method, yield line analysis and non linear fracture mechanics methods consider for analysis and design of slab on grade. Slab on grade should be sustainable to perform satisfactorily intended use and economical. To design slab on grade with minimum slab thickness and optimum dose of fiber based on serviceability criteria reflects sustainability construction approach.

Fiber reinforced concrete (FRC) is widely used as construction material. Fibers increase the structural integrity of concrete. Steel fibers, glass fibers, synthetic fibers and natural fibers are types of fibers used in FRC. Waste deposition of vehicles tyre after its useful life became critical issue to dispose off. In the present study preliminary investigation is carried out to check the feasibility of waste tyre tube material as fiber material in concrete. Waste tyre tube collected from different sources and cutting to aspect ratio 40 and called Rubber Tyre Tube Fiber (RTTF). Dose of RTTF is decided from the literature pertaining to FRC as 0.5%, 1.00% and 1.5% with respect to volume of concrete. Fresh and hardened properties of concrete are investigated with utilization of RTTF as fiber. Hardened state performance of RTTF reinforced concrete improved over the control mix. RTTF reinforced concrete is more crack resistance than control mix. Flow ability or workability of the concrete decrease with increment of dose of RTTF fiber because of formation of flocks. These flocks in the fresh concrete decrease the workability of concrete.

High Density concrete is commonly used for radiation shielding of nuclear-reactors and other structures like counter weights, coating of off-shore pipelines. High Density concrete or is designed by using heavy weight aggregates such as hematite, magnetite, barite etc. The material is called hematite is used in this special concrete. The mix used is for OPC 43grade of cement. High density concrete can be designed in same way as normal weight concretes, but the additional self-weight should be taken into account.