Nano technology is an emerging field of interest for civil engineering application. Among the nano materials presently used in concrete, nano-silica possess more pozzolanic nature. It has the capability to react with the free lime during the cement hydration and forms additional C-S-H gel giving strength, impermeability and durability to concrete. Present paper investigates the effects of addition of nano silica in normal strength concrete. Three types of nano-silica in the form of nano suspension having different amount of silica content have been investigated. Mix design has been carried out by using particle packing method. X-Ray diffraction (XRD) analysis has been carried out to find the chemical composition of control concrete and nano modified concrete. Further, experimental investigations have been carried out to characterize the mechanical behaviour in compression, tension and flexure. It has been observed that the addition of nano-silica in normal strength concrete increased the compressive strength and decreased the spilt tensile strength and flexural strength. Also, Rapid chloride permeability test (RCPT) has been conducted to know the chloride permeability of control concrete, nano modified concrete, and nano coated concrete. It has been observed that the chloride permeability is less for nano coated concrete.

In accordance with the principles of sustainable construction, the results of Life Cycle Assessment (LCA) technique are useful inputs to the decision-making process when designing a building. This article presents such an analysis of a finished building product, which is a modified concrete mix. The calculations took into account the phases of the A1–A4 cycle, i.e. from the extraction of raw materials to the transport of the finished material to the construction site. Test results for concrete mixes and 28-day solid concrete are presented in tabular form. Based on all the test results obtained, it was found that the addition of waste polypropylene fibres has a positive effect on the key properties for the floor concrete. It has been found that proper processing of banding tapes or other polypropylene waste into macro-fibres can be a good example of proper waste management and can contribute to a significant reduction in residual waste. This additive is emission-free and sourced from recycling, making it an excellent alternative to commonly used dispersed reinforcement.