Safiuddin Md, Raman Sudharshan N, Zain Muhammad Fauzi Mohd
Angelo Del Zotto School of Construction Management, George Brown College, 146 Kendal Avenue, Toronto, ON M5T 2T9, Canada.
Department of Architecture, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia.
Materials (Basel). 2015 Dec 10;8(12):8608-8623. doi: 10.3390/ma8125464.
The aim of the work reported in this article was to investigate the effects of medium temperature and industrial by-products on the key hardened properties of high performance concrete. Four concrete mixes were prepared based on a water-to-binder ratio of 0.35. Two industrial by-products, silica fume and Class F fly ash, were used separately and together with normal portland cement to produce three concrete mixes in addition to the control mix. The properties of both fresh and hardened concretes were examined in the laboratory. The freshly mixed concrete mixes were tested for slump, slump flow, and V-funnel flow. The hardened concretes were tested for compressive strength and dynamic modulus of elasticity after exposing to 20, 35 and 50 °C. In addition, the initial surface absorption and the rate of moisture movement into the concretes were determined at 20 °C. The performance of the concretes in the fresh state was excellent due to their superior deformability and good segregation resistance. In their hardened state, the highest levels of compressive strength and dynamic modulus of elasticity were produced by silica fume concrete. In addition, silica fume concrete showed the lowest level of initial surface absorption and the lowest rate of moisture movement into the interior of concrete. In comparison, the compressive strength, dynamic modulus of elasticity, initial surface absorption, and moisture movement rate of silica fume-fly ash concrete were close to those of silica fume concrete. Moreover, all concretes provided relatively low compressive strength and dynamic modulus of elasticity when they were exposed to 50 °C. However, the effect of increased temperature was less detrimental for silica fume and silica fume-fly ash concretes in comparison with the control concrete.
本文所报道工作的目的是研究中温和工业副产品对高性能混凝土关键硬化性能的影响。基于水胶比0.35制备了四种混凝土混合料。除了对照混合料外，使用硅灰和F类粉煤灰这两种工业副产品分别以及与普通硅酸盐水泥一起制备了三种混凝土混合料。在实验室中对新拌混凝土和硬化混凝土的性能进行了检测。对新拌混凝土混合料进行坍落度、坍落扩展度和V型漏斗流动度试验。将硬化混凝土在20、35和50℃下养护后进行抗压强度和动态弹性模量试验。此外，在20℃下测定了混凝土的初始表面吸水率和水分进入混凝土的速率。新拌混凝土由于其优异的变形能力和良好的抗离析性，性能极佳。在硬化状态下，硅灰混凝土的抗压强度和动态弹性模量最高。此外，硅灰混凝土的初始表面吸水率最低，水分进入混凝土内部的速率也最低。相比之下，硅灰-粉煤灰混凝土的抗压强度、动态弹性模量、初始表面吸水率和水分迁移速率与硅灰混凝土相近。此外，所有混凝土在50℃下养护时，抗压强度和动态弹性模量都相对较低。然而，与对照混凝土相比，温度升高对硅灰混凝土和硅灰-粉煤灰混凝土的影响较小。
