Abstract:

                             Modern world emerges with new techniques in construction field. Concrete technology has made tremendous strides in the past decade. The development in specifying the concrete according to its performance requirements, rather than its constituents and ingredients has opened innumerable opportunities for both producers and users of concrete to design concrete catering to their specific requirements. One of the most outstanding advances in the concrete technology over the last decade has been “Lightweight Concrete” (LWC).

                In this study, Coconut Coir Fiber Aggregates (CCFA) are used as a lightweight coarse aggregate in concrete, by partially and completely replacing the conventional coarse aggregate in concrete. The present experimental work is aimed at studying the behaviour of LWC with different percentages of CCFA in M20 grade of concrete mix with convenient dosage of  super plasticizer so that the workability is maintained more or less constant  The concrete mix adopted in this investigation is designed with reference to IS 10262 (2009) [1]. Five different concrete mixes namely, one with conventional coarse aggregate in concrete and the remaining four mixes with CCFA replacing the conventional coarse aggregate in 25, 50, 75 and 100 percentages on volume basis are considered in this experimental work. The mechanical properties such as cube compressive strength, splitting tensile strength, flexural strength, impact strength, shear strength in mode-II fracture, modulus of elasticity and density at the age of 28 days are determined. Totally 120 concrete specimens are cast for five types of concrete mixes mentioned above.

Key words: Coconut Coir Fiber Aggregates (CCFA), double centered notch (DCN), flexure, impact, split tension, compression.