Shahrul Syafiqah, Mohammed Bashar S, Wahab M M A, Liew M S
Civil and Environmental Engineering Department, Faculty of Engineering, Universiti Teknologi PETRONAS (UTP), Bandar Seri Iskandar 32610, Perak, Malaysia.
Materials (Basel). 2021 Sep 23;14(19):5496. doi: 10.3390/ma14195496.
Crumb rubber (CR) from scrap tires is used as a partial replacement of fine aggregates in cement paste. This promotes the sustainable development of the environment, economy, and society, as waste tires are non-biodegradable and flammable. They occupy large landfill areas and are breeding grounds for mosquitoes and rodents. Inclusion of CR in mortar leads to several improvements on the mixture properties such as ductility, toughness, and impact resistance. However, it exhibits lower strengths and Modulus of Elasticity (ME). Therefore, to promote the use of mortar containing CR, it is vital to improve its mechanical strength. Past studies proved that nano-silica (NS) improves the strength of concrete due to the physico-chemical effects of NS. This study aims to examine the mechanical properties of crumb rubber mortar containing nano-silica (NS-CRM) and to develop models to predict these properties using Response Surface Methodology (RSM). Two variables were considered, CR as partial replacement to sand by volume (0%, 7.5%, 15%), and NS as partial replacement to cement by weight (0%, 2.5%, 5%). The results demonstrated a significant improvement in the mechanical properties of CRM when incorporating NS, and the models developed using RSM were acceptable with a 2% to 3% variation.
废旧轮胎的胶粉（CR）被用作水泥浆体中细集料的部分替代品。这促进了环境、经济和社会的可持续发展，因为废旧轮胎不可生物降解且易燃。它们占据了大片填埋区域，是蚊子和啮齿动物的滋生地。在砂浆中加入CR可使混合物的性能得到多项改善，如延展性、韧性和抗冲击性。然而，它的强度和弹性模量（ME）较低。因此，为了推广含CR砂浆的使用，提高其机械强度至关重要。过去的研究证明，由于纳米二氧化硅（NS）的物理化学作用，它能提高混凝土的强度。本研究旨在研究含纳米二氧化硅的胶粉砂浆（NS-CRM）的力学性能，并使用响应面法（RSM）建立预测这些性能的模型。考虑了两个变量，CR按体积作为砂的部分替代品（0%、7.5%、15%），NS按重量作为水泥的部分替代品（0%、2.5%、5%）。结果表明，加入NS后CRM的力学性能有显著改善，使用RSM建立的模型在2%至3%的变化范围内是可接受的。
