This study aims at evaluating the effect of ultrafine granulated copper slag (UGCS) on hydration development of blended cement and mechanical properties of mortars. The UGCS with the median particle size of 4.78 μm and BET surface area of 1.31 m2/g was used as a cement replacement to prepare blended cements. Hydration heat emission of blended cement and mechanical performance of mortars were investigated by using isothermal calorimetry and strength tests, respectively. X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were applied to the analysis of pozzolanic reaction and hydration products. The results illustrate that UGCS has influence on the hydration heat evolution of blended cement due to its filler effect and pozzolanic reaction. The cumulative hydration heat of blended cement is reduced by partial cement replacement with UGCS. The test mortar prepared by using blended cements with 30 wt. % UGCS shows a retardation of strength development with a low value at early ages (7 days) and a rapid growth at later ages (28 days). The 90-day compressive strength of test mortar is 45.0 MPa close to that of the control mortar (49.5 MPa). The obtained results from XRD and TGA analysis exhibit an increase in calcium hydroxide (CH) consumption and calcium silicate hydrates (C–S–H) formation in blended cement pastes with curing time. The cement replacement with UGCS induces changes in microstructure of blended cement paste and chemical composition of hydration products.
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机译：这项研究旨在评估超细颗粒铜渣（UGCS）对混合水泥水化发展和砂浆力学性能的影响。用中值粒径为4.78μm，BET表面积为1.31 m 2 / g的UGCS代替水泥制备混合水泥。分别通过等温量热法和强度试验研究了掺合水泥的水化放热和砂浆的力学性能。 X射线衍射（XRD），热重分析（TGA）和扫描电子显微镜（SEM）被用于火山灰反应和水合产物的分析。结果表明，UGCS由于其填料效应和火山灰反应而影响了掺合水泥的水化热演化。通过用UGCS替代部分水泥，可降低混合水泥的累积水合作用热量。通过使用30重量％的混合水泥制备测试砂浆。 ％UGCS显示出强度发展的延迟，在早期（7天）低，而在晚期（28天）快速增长。试验砂浆的90天抗压强度为45.0 MPa，接近于对照砂浆的抗压强度（49.5 MPa）。通过XRD和TGA分析获得的结果显示，随着固化时间的延长，混合水泥浆中氢氧化钙（CH）的消耗量和硅酸钙水合物（CS–H）的形成增加。用UGCS替代水泥会引起混合水泥浆的微观结构和水合产物化学成分的变化。
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