【摘要】 研究采用碳化钢渣陶砂作为集料，并复配碳酸锂和硼酸调控伸缩缝混凝土性能，制备出超早强补偿收缩现浇超高性能混凝土。通过凝结时间试验、力学性能试验、自收缩试验对混凝土的早期强度、体积稳定性等性能的演变规律进行了研究分析；采用水化热、SEM以及²⁹Si NMR对混凝土的水化进程、微观形貌以及凝胶结构组分进行表征探讨。研究发现，碳酸锂的掺加能促进长针状钙矾石的生成，填补混凝土的孔隙结构，提高早期强度和体积膨胀率；硼酸的掺加会延迟水泥水化，保证混凝土的工作性能。通过调控碳酸锂和硼酸掺量能将混凝土的早期性能调控在可接受范围内。最后，对超早强补偿收缩现浇超高性能混凝土进行了现场应用，应用效果良好。更多还原

【Abstract】 The ultra-early strength and shrinkage-compensating cast-in-place ultra-high performance concrete was prepared by using carbonized steel slag and pottery as aggregate,combined with lithium carbonate and boric acid to regulate the performance of expansion joint concrete.The evolution laws of early strength,volume stability and other properties of concrete were studied and analyzed through setting time experiments,mechanical properties experiments,and autogenous shrinkage experiments.The hydration process,microstructure and gel structure components of concrete were characterized and discussed by using hydration heat,SEM and²⁹Si NMR.The study found that the addition of lithium carbonate can promote the formation of long needle-like ettringite,fill the pore structure of concrete,and improve early strength and volume expansion;the addition of boric acid can delay cement hydration and ensure the working performance of concrete.By adjusting the content of lithium carbonate and boric acid,the early performance of concrete can be adjusted within an acceptable range.Finally,the ultra-early strength shrinkage-compensated cast-in-place ultra-high performance concrete was applied in situ,and the application effect was good.更多还原