Study of strength and rate of drying of cement paste due to W/C ratio, surface area, thickness and compactness

• Main Author: Phua, So Bing.
• Other Authors: Lye Sun Woh
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/54556
• Institution: Nanyang Technological University

In this report, the effects of 4 different factors such as water cement ratio, surface area measured in terms of lap length, thickness and compactness of paste on its strength and rate of drying are studied. Vacuum drying was used as the means of speeding up the drying process. The experiments were carried out with each factor based on three different levels. The change in strength as well as weight loss is observed as the factor varies from level 1 to level 3. In the study of rate of drying, weight loss is used as a measure of efficiency of drying. The results focus on the rate of drying rather than the time required for the cement paste to be fully dried. Factors related to the external geometry such as surface area and thickness was seen as the more influential factors as compared to the w/c ratio and porosity. In the study of strength, despite numerous studies done on compressive strength, the project study the effects of various factors on its tensile and shear strength. Porosity, a measure of volume of gaps, voids and pores, strongly influenced the strength of hardened cement paste as well as the bond strength between the paste and the floor tile. Hence w/c ratio and compactness ratio as a direct influence on the porosity of the mixture hence were the more influential factor in the measure of strength. However, the research has only covered several aspects in the study of cement paste. Numerous factors were not considered in the project. Factors such as temperature, curing time, chemical reaction within the cement powder and water. Further research would be recommend on these areas to generate a more conclusive aspect of the effect on the 4 factors discussed in this project.