Abstract

This study seeks to modulate the properties of gypsum-fibre-cement composite with 0.05 and 0.1 grammes of water proof chemical admixture. The effect of these additions on the prolonged water absorption (PWA), mechanical properties and thermal degradation were studied. Sample with composition of 50:50 of cement:gypsum + admixture + fibre had minimal PWA due to the development of silane based lamellar structure. This structure similarly led to significant enhancement in the values of compressive strength (max at 23 MPa), modulus of rupture (max at 10 N/mm²) and modulus of elasticity (max at 5542 N/mm²) respectively. The thermal degradation curves from TG/DTA analysis showed that composition of 50:50 gypsum:cement + additive + fibre was thermally more stable than the remaining samples due to the influence of the added natural fibres which acted as the insulator. Thus, the water absorption potential was largely dependent on the presence of the added chemical admixture while the synergy among the fibre, gypsum and cement were responsible for the enhanced thermo-mechanical properties.

摘要

本研究旨在用 0.05 克和 0.1 克的防水化学外加剂来调节石膏-纤维-水泥复合材料的性能。研究了这些添加物对延长吸水率 (PWA)、机械性能和热降解的影响。由于硅烷基层状结构的发展，水泥：石膏 + 外加剂 + 纤维组成为 50:50 的样品具有最小的 PWA。这种结构同样显着提高了抗压强度（最大值为 23 MPa）、断裂模量（最大值为 10 N/mm ²）和弹性模量（最大值为 5542 N/mm ²） 分别。TG/DTA 分析的热降解曲线表明，由于添加的作为绝缘体的天然纤维的影响，50:50 石膏：水泥 + 添加剂 + 纤维的组合比其余样品的热稳定性更高。因此，吸水潜力在很大程度上取决于添加的化学混合物的存在，而纤维、石膏和水泥之间的协同作用是提高热机械性能的原因。