Influence of nano-CaCO3 addition on the compressive strength and microstructure of high volume slag and high volume slag-fly ash blended pastes (Retracted article. See vol. 50, 2022)
Influence of nano-CaCO3 addition on the compressive strength and microstructure of high volume slag and high volume slag-fly ash blended pastes (Retracted article. See vol. 50, 2022)
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DOI：
10.1016/j.jobe.2019.100929
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发表时间：
2020-01-01
影响因子：
6.4
通讯作者：
Shaikh, Faiz Uddin Ahmed
中科院分区：
文献类型：
--
作者：
Hosan, Anwar;Shaikh, Faiz Uddin Ahmed
研究了纳米碳酸钙（NC）掺量对大掺量矿渣（HVS）浆体和大掺量矿渣-粉煤灰（HVSFA）混合浆体28 d抗压强度和微观结构的影响。结果表明，掺量为1-4%的NC可使矿渣含量为70%、80%和90%的HVS浆体的抗压强度分别提高8- 24%、1-16%和2-20%。由于添加1- 4%NC，含有70%的组合矿渣和粉煤灰含量的HVSFA浆体的抗压强度也比参考对照浆体显著增加16-24%，并且在28天的养护后保持比OPC浆体更高的抗压强度。NC的加入减少了HVS糊剂和HVSFA糊剂的大毛细孔和累积孔体积。通过热重分析（TGA）发现，NC的加入使含70%矿渣粉煤灰的HVSFA浆体中氢氧化钙（CH）含量显著降低，而HVS浆体中CH含量略有增加。在扫描电子显微镜（SEM）图像和EDS痕量分析中，所有HVS和HVSFA浆料中由于添加NC而显示出具有较少内部微裂纹和更多水化产物的致密微观结构。HVS和HVSFA浆体与对照水泥浆体相比具有显著更低的碳足迹和更高的抗压强度，可以通过包含1%NC来实现。
This paper presents the effects of various nano-CaCO3 (NC) contents on 28 days compressive strength and microstructure of high volume slag (HVS) pastes and high volume slag-fly ash (HVSFA) blended pastes. The results show that addition of 1-4% NC improved the compressive strengths of HVS pastes containing 70%, 80% and 90% slag, respectively by 8-24%, 1-16% and 2-20% compared to their reference pastes. The compressive strength of HVSFA paste containing combined slag and fly ash content of 70% is also increased significantly by 16-24% than the reference control paste due to the addition of 1-4% NC and maintained higher compressive strength than OPC paste after 28 days of curing. The addition of NC reduced the large capillary pores and cumulative pore volume of HVS pastes and HVSFA paste. Significant reduction of calcium hydroxide (CH) in HVSFA paste containing combined slag and fly ash content of 70% is found due to the addition of NC by thermogravimetric analysis (TGA) and a slight increase of CH is noticed in all HVS paste. A denser microstructure with fewer internal micro-cracks and more hydrated products are revealed in scanning electron microscopic (SEM) images and EDS trace analysis in all HVS and HVSFA pastes due to the addition of NC. HVS and HVSFA paste with significantly lower carbon footprint and higher compressive strength than control cement paste can be achieved with the inclusion of 1% NC.