Feasibility of Natural Clay Additives in Cement Mortar
This work investigated the possibility of using natural clays as additives in cement- sand mortar. Natural clays were collected from three different locations in Sri Lanka for this study. Collected clays were refined and milled as powder by using mortar and pestle, and possible standard methods. A homemade ball mill machine was used to crush the powdered clay further and mixed with cement. The bricks and pellets were casted separately by used the pure clays. Mortar blocks and pellets were prepared with clay additive percentages of 10 wt% and 20 wt% of replacement in the cement; samples were prepared with the ratio of cement and sand volume quantity in 1:3. The casted bricks and blocks were used to investigate the compressive strength and water absorption of the samples. According to the result of the study, compressive strength values of the cement mortar with additive clay samples were increased between about 45 and 83 MPa. The water absorption of the samples with additives was very close values. The density and compressive strength of the samples apparent polynomial trend line against water absorption, with regression coefficient of 0.936 and 0.366 respectively. The samples manifest, when density was reached almost half of its initial value while water absorption was doubled of its initial value. The water absorption of the samples was dramatically doubled while compressive strength was the half of its initial value. Pellet samples were used to determine the thermal conductivity and electrical conductivity. The electrical conductivity values were not much vary among them. Thermal conductivity values of the samples with additives were clearly disclosed slight increment but samples casted by pure clays were shown marginal decrement of those values. Cement mortar with additive clay exhibited higher compressive strength, because have more homogeneity binder, less pores, and higher level of adhesion at interfacial zone.
Sitpalan A, Ananda EMS, Aashik AR, Preththiha V, Rajitha VKM and Suventhiran S