Compressive Strength and Chloride penetration on Semi-Lightweight Concrete Made Up of Artificial Aggregates

Abstract

 This paper deals with the properties of semi-Light weight concrete prepared by using Light weight wood ash pellets as coarse aggregates. It can be prepared by varying the cement content from 300 to 450 kg/m³. Optimum design mix can be finalised by studying the engineering properties such as compressive strength, split tensile strength, young’s modulus and rapid chloride penetration test. Various trial mixes have been attempted in the laboratory by altering cement content, water/cement ratio and water absorption of the coarse aggregate. The scope of this study is to find the optimum mix design of semi-light weight concrete using wood ash pellets. In this research, 16 trial mixes were designed as per ACI method. The relationship between the compressive strength vs w/c ratio of various trial mixes and also, the relationship between cement content vs w/c ratio were plotted. From the test results, three mixes were finalised based on its compressive strength and slump value with a cement content of 300 kg/m³, 400 kg/m³, 450 kg/m³. The 28^th day compressive strength of the above mentioned three finalised mixes was reported to be 24.3 MPa, 26.6 MPa, 28.2 MPa. The 28^th day split tensile strength of finalised mixes was reported to be 2.48 MPa, 2.51 MPa, 2.54 MPa. Similarly, the 28^th day compressive strength of cylinders of finalised mixes was reported to be 17.85 MPa, 23.05 MPa, 24.71 MPa. Stress - strain behaviour and rapid chloride ion penetration(RCPT) of finalised mixes were also studied. From the test results, the mix with cement content of 450 kg/m³ has achieved maximum 28^th compressive strength of 28.2 MPa with w/c ratio of 0.3.

Keywords: Semi-light weight concrete, Wood ash pellets, compressive strength, stress-strain behaviour, RCPT