Experimental study on bendable concrete

Abstract

Reducing the brittle nature of concrete has opened a new world of possibilities to enhance the safety, durability and sustainability of the next generation of civil infrastructure. Tiny fibres partly account for its performance, and also the materials are designed for maximum flexibility, because of its long life, the Engineered Cement composites (ECC) is expected to cost less in the long run, as well. The ductile or bendable concrete is made of same ingredients as in regular concrete minus the coarse aggregate. It looks exactly like normal concrete, but under excessive strain, the ECC concrete allows, the specially coated network of fibre in the cement to slide within the cement, thus avoiding the inflexibility that causes brittleness and breakage. The key factor is that ECC is engineered, means in addition to reinforcing the concrete with micro scale fibers that act as ligaments to bond the concrete more tightly As this is a special type of concrete there are no defined codes for it and also it is rarely developed in India hence no Indian Codes can be found related to this, thus for these reasons the parameters needed are to be obtained using trial and error method. This project includes different sets of tests such as marsh-cone test, slump test, sieve analysis, compression test, split tensile test and flexure test. To get the perfect dosage of admixtures marsh-cone test if well known for giving reliable results, similarly sieve analysis gives us the optimum sizes and proportion of the fine aggregates to be used in the making of this concrete. To determine the best possible water-cement and sand-cement ratio compression test was practiced and also it gives us the compressive strength of the concrete specimen. Finally the flexural strength of the concrete is determined by performing the flexural test on the specimen / member. Later on all the data is analysed and future predictions for flexural strength corresponding to different intermediate depths are made in regards to the results obtained. Also the ECC is compared with conventional concrete with regard to its weight and cost parameters.