A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1984

Two commercially available superplasticizers and two types of additives derived from sugar cane bagasse and rice straw which are collected from different local paper factories in Thailand were used in different concrete mixes to examine the feasibility f o r use as water-reduced and f lowing concretes. Tests were made with different mix proportions and the effects of types a nd dosages of admixtures on the mechanical properties of concrete namely compressive strength, modulus or rupture a nd modulus o f elasticity were investigated. The test results indicated that the commercially available superplasticizers remarkably improved the mechanical properties of water-reduced concrete and greatly increased the workability of flowing concrete without adversely affecting the strengths. For water-reduce d concrete, the additive derived from sugar can e bagasse is considered to be suitable for use but its efficiency is low compared to the commercial superplasticizers. The other additive derive d from rice straw is found to be of inferior quality than the one derives from sugar cane bagasse. An adverse effect on later strengths t or rich mixes was observe educing this type of additive. For flowing concrete, the additive derived from sugar cane bagasse is economically feasible to be used with a dosage limit of 2%.