摘 要：从石灰石粉对C3S、C3A和水泥混凝土水化影响方面入手，阐述了水泥-石灰石粉胶凝体系的水化特性，并在此基础上，进一步从石灰石粉对水泥基材料流变性、强度、尺寸稳定性、耐久性的影响等方面，综述了水泥-石灰石粉胶凝材料的国内外研究现状。针对现有水泥-石灰石粉基材料研究存在的问题，探讨了全面、系统研究水泥-石灰石粉胶凝体系的重要性。 Abstract: The hydration characteristic of cement-limestone power cementitious system is described based on the effect of limestone power on the hydration of C3S, C3A and cement concrete. On the basis of above all, the research status at home and abroad of the cement-limestone power cementitious material is summarized from the influences of limestone power on the rheology, strength, dimensional stability and durability of cement-based materials. Aiming at the problems of the present limestone powder cement-based material research, the importance of completely and systematically studying the cement-limestone power cementitious system is discussed.

摘 要：在全球面临能源日益枯竭、环境严重污染、气候不断恶化的今天，全社会各行各业都应发展低碳经济。商品混凝土行业向低碳化发展亦是大势所趋。通过调研，提出了商品混凝土行业低碳化发展的十个具体途径。 Abstract: Nowadays, the problems such as energy exhaustion, environment pollution and ?climatic deterioration, the low carbon economy should be developed in all the industries. And the ready-mixed concrete industry should also be developed into the low carbon industry. Through the investigation, the ten measures for the ready-mixed concrete industry developed into the low carbon industry are proposed.

摘 要：以西安地铁主体结构工程施工为例，介绍了钢纤维混凝土在该工程地裂缝段及车站主体结构中应用的施工要点及质量控制措施。 Abstract: Taking the construction of Xi’an Metro main structure project as an example, the construction points and quality control measures of the ground cracks and station main structure are introduced which are applied by steel fiber reinforced concrete.

摘 要：探讨了排水管钢筋骨架滚焊机生产范围划分的合理性，从理论上分析了合理调节焊接参数在滚焊机使用过程中的重要性，列举了滚焊机常见故障的排除方法和节能降耗的具体措施，探讨了造成钢筋骨架不合格的原因，并提出了相应的解决方案。 Abstract: How to rationally divide the production scope of reinforced skeleton frame roll welders for drainage pipes is discussed. The importance of reasonably adjusting the welding parameters in the process of using roll welders is theoretically analyzed. Meanwhile, the solving methods of common stoppages of roll welders and measures of energy saving are listed. In addition, the reasons why reinforced skeleton frames are unqualified are discussed, and relevant solving ways are put forward.

摘 要：通过大量文献资料的研究与对比分析，对预应力混凝土结构火灾的研究现状进行了综述，包括高温（火灾）条件下预应力钢筋和预应力混凝土结构退化规律试验研究现状、温度场的计算、构件承载力计算以及防火和灾后处理等，展望了今后的研究方向。 Abstract: Based on the comparative and analytical investigation on large number of research references, the research summarization on fire-resistant performance of the prestressed concrete structures is carried out, which includes the study status of the deterioration law of prestressed reinforcement and prestressed concrete structure at high temperature condition, the calculation of the temperature field, the calculation of loading capacity of structure members, fire prevention and the treatment of post-disaster, etc. And the future research directions are prospected.

摘 要：参照普通混凝土配合比设计方法配制再生粗骨料混凝土，采用相同尺寸和配筋率制作了6根再生混凝土简支梁和2根普通混凝土简支梁，进行静力加载试验。结果再生粗骨料取代率为30%时，再生混凝土梁的极限弯矩最大。用普通混凝土公式计算再生混凝土梁的开裂弯矩时，当再生粗骨料取代率大于50%时，建议修正系数取0.7；用普通混凝土公式计算再生混凝土梁正截面的极限承载力时，计算结果与试验结果符合较好。 Abstract: Recycled coarse aggregate concrete is prepared based on the mix ratio design method of normal concrete. And 6 recycled aggregate concrete beams and 2 natural aggregate concrete beams with the same section size and same percentage of reinforcement are prepared, and the static loading test is carried out. The results show that the ultimate bending moment of recycled aggregate concrete beams is the largest when the replacement ratio of recycled coarse aggregates is 30%. The correction coefficient is suggested to take 0.7 when the replacement ratio of recycled coarse aggregates is more than 50% and when the cracking moment of recycled aggregate concrete beams is calculated by ordinary concrete formula. It is still feasible to calculate the ultimate loading capacity of normal section of recycled aggregate concrete beams with ordinary concrete formula.