Comparative Analysis of Chemical and Natural Admixture in Concrete

Abstract

Concrete's compressive strength and splitting tensile strength are two major problems. This study investigates the use of natural and chemical admixtures to increase the compressive and splitting tensile strength of concrete and to make it more costeffective. In our project, concrete cylinders with and without admixtures are formed, and their compressive strength is assessed 7, 14, and 28 days after curing. The results of both concrete categories are contrasted. Investigating the increase in compressive and splitting tensile strength caused by chemical and natural admixture is the main goal of this study. In this thesis project, we prepared four sets of 18 cylinder samples each, for a total of 72 cylindrical samples. We followed the guidelines for ASTM standards when working on this project. We used the M20 standard concrete grade, and the mix ratio was 1:1.5:3. We used the same quantity of cement, coarse aggregate, fine aggregate, and w/c ratio in each sample. One set of these was created without the use of admixture, while the remaining three were created using two chemical and one natural admixture in the same quantity of 7.2 ml. We investigated the compressive and splitting tensile strengths following three cycles of curing for 7, 14, and 28 days. After 28 days, the compressive strength measured 2372 psi without admixture, 2969 psi with 7.2 ml of self-compacting admixture, 2707 psi with 7.2 ml of gram flour as admixture, and 3201 psi with 7.2 ml of gram flour (using 7.2 ml high strength admixture).After 28 days of curing, the splitting tensile strength measured 309 psi without admixture, 365 psi with 7.2 ml of self-compacting admixture, 348 psi with 7.2 ml of gram flour as an admixture, and 448 psi with 7.2 ml of gram flour (using 7.2 ml high strength admixture). Here the amount of used admixture was 1% of the used cement weight. The additional cost for chemical admixture is 1.1 taka per sample and for gram flour the cost is 0.5 taka per sample. Comparing all of resultswe can say that natural admixture (Gram flour) isa suitable alternative to chemical admixture comparing economicaleffectand strength. Throughout the thesis study, all codes and conducts were upheld in accordance with ASTM standard requirements.. Keywords Concrete,M20 Grade concrete PCC,Compressivestrength,Splitting tensile strength,