Suitability of Crushed Ceramic and Porcelain Clay Tiles as Partial Replacement of Cement in Concrete

Abstract

The increased demand for construction over the past two decades has led to drastic increase in the cost of concrete production. The increasing cost and scarcity of Portland cement has impacted negatively on the delivery of affordable housing and infrastructural development in developing countries like Uganda. For this reason, there is urgent need for finding suitable alternatives which can replace cement partially or at a high proportion. This study focussed on establishing the feasibility of using crushed ceramic and porcelain clay tiles powder as partial replacement of cement in production of eco-friendly concrete. Samples of ceramic and porcelain clay tiles were taken in accordance to BS 1881-101: 1983, which gives methods of sampling. Fifty kilograms of each material was picked from each of the 20 sampled sites within Kampala metropolitan area. X-Ray Fluorescence Spectrometer method was used to determine the chemical composition of the ceramic and porcelain clay tile powders while the physical properties were determined using the ASTM C187 and ASTM C188. A comparison between the properties of the waste materials and cement was made to verify if its composition warrants it to be used as a pozzolan. Concrete cubes measuring 150 mm × 150 mm × 150 mm and 100 mm × 200 mm cylinder specimens were made from seven different concrete mixes prepared by using crushed ceramic and porcelain clay tile powder to replace 0, 5, 10, 15, 20, 25 and 30% of ordinary Portland cement (grade 42.5) by mass. The workabilities of the fresh concrete mixes were evaluated using the slump test while compressive and splitting tensile strengths of hardened concrete were evaluated at different curing periods of 7, 14 and 28 days. The Civil Engineering Standard Method of Measurement was used to evaluate the cost of concrete production. Two indicators (abiotic deletion and global warming) were xxii used to evaluate the environmental impacts. The properties of ceramic and porcelain powders showed that the combined percentage of silica, iron oxide, and alumina for both materials met the 70% minimum requirement of ASTM C 618 for a good pozzolan. The results of slump test showed that increase in ceramic and porcelain powder replacement decreased the workability of concrete. Replacement of cement with ceramic and porcelain powder significantly increased the compressive strength of concrete. The target compressive and tensile splitting strengths were achieved up to 20% replacement of cement with ceramic and porcelain powder beyond which the strength reduced. The cost evaluation indicated there was a reduction of 15.2% between the conventional and optimal mixes. Energy consumption reduced by 12.8%, signifying a reduction in the production cost of binders. Finally, carbon dioxide emission reduced by 19.2% implying a significant reduction in global warming.