This study investigates the effects of incorporating rice husk ash (RHA) on the characteristics of lightweight geopolymer concrete (LWGC), which includes waste tire aggregate (WTA). This study utilized RHA to replace 15 % of ground blast furnace slag (GBFS) in LWGC. The LWGC also included WTA as a partial substitute for pumice aggregate, with varying rates of 10 %, 25 %, and 50 % by volume. In addition, curing temperatures of 75 °C and 100 °C were utilized for 3 h following the casting process. 16 LWGC blends were created, each with a dry density below 1800 kg/m. To study the features of hardened LWGC, various tests included apparent porosity, water absorption, capillary water absorption, dry density, compressive and flexural strength. In addition, freezing and thawing cycles (20, 40, and 60 cycles) and elevated temperatures of 250 and 500 °C affect compressive strength and density loss in addition to examining the thermal conductivity coefficient and morphological imaging by SEM on microscopic structure. The results showed that adding 15 % RHA as a partial replacement for GBSF led to a decrease in the density of hardened concrete to about 1561 kg/m. At the same time, the compressive strength decreased to 24 and 21 MPa for the samples subjected to 75 and 100 °C heat treatments, respectively. Including 15 % RHA also reduced the thermal conductivity coefficient to 0.978 W/mK. Regarding the inclusion of WTA as a substitute for pumice aggregate, it led to a decrease in density and compressive strength as the replacement rate increased. In addition, the thermal conductivity coefficient decreases to its lowest level when WTA replaces 50 % of the pumice.

中文翻译：

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稻壳灰对橡胶轻质地质聚合物复合材料物理机械、耐久性和微观结构特征的影响

本研究研究了掺入稻壳灰（RHA）对轻质地质聚合物混凝土（LWGC）（包括废轮胎骨料（WTA））特性的影响。本研究利用 RHA 替代 LWGC 中 15% 的磨细高炉矿渣 (GBFS)。 LWGC 还包括 WTA 作为浮石骨料的部分替代品，其体积比例分别为 10%、25% 和 50%。此外，在铸造过程后，采用 75 °C 和 100 °C 的固化温度 3 小时。创建了 16 种 LWGC 混合物，每种混合物的干密度均低于 1800 kg/m3。为了研究硬化LWGC的特性，进行了各种测试，包括显气孔率、吸水率、毛细管吸水率、干密度、压缩和弯曲强度。此外，除了通过 SEM 检查微观结构的导热系数和形态成像之外，冷冻和解冻循环（20、40 和 60 个循环）以及 250 和 500 °C 的高温也会影响抗压强度和密度损失。结果表明，添加 15% RHA 作为 GBSF 的部分替代，导致硬化混凝土的密度降低至约 1561 kg/m。同时，经过75℃和100℃热处理的样品的抗压强度分别下降至24和21MPa。添加 15% RHA 还将导热系数降低至 0.978 W/mK。关于WTA作为浮石骨料的替代品，随着替代率的增加，导致密度和抗压强度下降。此外，当WTA取代50%的浮石时，导热系数降至最低水平。