Physico-Mechanical Characterization of Gypsum-Agricultural Waste Composites for Developing Eco-Friendly False Ceiling Tiles

Abstract

This paper aims to facilitate in the reduction of issues related to agricultural wastes such as disposal and burning by incorporating two widely produced agricultural wastes in Pakistan, i.e., Rice Husk and Wheat Straw, in gypsum false ceiling plates to develop an eco-friendly construction product. There is an increased focus of research on the development of such eco-friendly gypsum products to make the use of gypsum sustainable. Composites containing agricultural residues with four different replacement levels of 2.5%, 5%, 7.5%, and 10% by weight are developed along with a control mix containing 100% gypsum. The physical, mechanical, and thermal properties of the developed composites are investigated. Also, the false ceiling plates are made using the developed composites and their flexural behavior is compared with that of the control specimen containing 100% gypsum. The results showed that density and shore C hardness reduced with increasing the amount of agricultural waste while the water absorption remained similar up to a dosage of 7.5%. Except for the 10% wheat straw dosage, flexural and compressive strength of developed composites showed a decrease with the increase of wheat straw and rice husk dosages but remained above the acceptable values of 1 MPa and 2 MPa, respectively, as per BS EN 14246. For the same replacement level, the composites containing wheat straw showed relatively inferior mechanical properties results as compared to those containing rice husk. The thermal conductivity test showed better thermal performance of the composite mixes as compared to the reference mix. The bending test on false ceiling plates showed that all the plates satisfied the minimum flexural strength criteria as per BS EN 14246 and the flexural strength of plates increased up to a replacement level of 5% for both the agricultural wastes.