摘   要：针对桥梁伸缩缝过渡区频繁出现的混凝土破损问题，研发了一种用于桥梁伸缩缝过渡区修复的硅酸盐-硫铝酸盐复合水泥胶凝材料体系超高性能混凝土（UHPC），并对其性能及微观结构进行了研究；优选了硫铝酸盐水泥的掺入比例，在某公路伸缩缝修复工程中进行了实际应用。结果表明：合适掺量的硫铝酸盐水泥能够有效提高UHPC的综合性能；当硫铝酸盐水泥质量为水泥总质量的10%时，所制备的UHPC在实际修复工程中的应用效果较好，养护24 h后抗压强度已经达到40 MPa。 Abstract: In response to the frequent occurrence of concrete damage in the transition zone of bridge expansion joints, a ultra-high performance concrete(UHPC) based on silicate sulfoaluminate composite cement cementitious material system was developed for the repair of bridge expansion joint transition zone, and its performance and microstructure were studied. The mix proportion of sulfoaluminate cement was optimized, which was actually applied in a highway expansion joint repair project. The results show that a suitable amount of sulfoaluminate cement can effectively improve the comprehensive performance of UHPC. When the mass of sulfoaluminate cement is 10% of the total cement mass, the prepared UHPC has a good application effect in practical repair project, and the compressive strength has reached 40 MPa after 24 h curing.

李响,王佳男,胡江海,等.基于复合胶凝材料体系的超高性能混凝土性能研究[J].混凝土与水泥制品,2024(2):1-5. LI X,WANG J N,HU J H,et al.Research on performance of ultra-high performance concrete based on composite cementitious material system[J].China Concrete and Cement Products,2024(2):1-5.

摘   要：在透水混凝土中掺入硅灰和矿粉，设计了四因素四水平正交试验，采用极差法分析了目标孔隙率、水胶比、硅灰掺量、矿粉掺量对透水混凝土抗压强度和透水性能的影响，并对其微观形貌进行了分析。结果表明：各因素对透水混凝土抗压强度和透水性能影响的大小顺序为目标孔隙率＞水胶比＞硅灰掺量＞矿粉掺量；透水混凝土的抗压强度和透水系数之间呈负相关关系；微观分析发现，未掺硅灰、矿粉的透水混凝土微观结构存在明显孔洞，硅灰或矿粉的掺入可以对孔洞进行有效填充，在一定程度上减少了孔隙数量，可改善透水混凝土的综合性能。 Abstract: A four factor and four level orthogonal test was designed by adding silica fume and mineral powder to pervious concrete. The range analysis method was used to analyze the effects of target porosity, water cement ratio, silica fume content, and mineral powder content on the compressive strength and permeability of pervious concrete, and the microstructure was analyzed. The results show that the order of influence of various factors on the compressive strength and permeability of pervious concrete is target porosity>water cement ratio>silica fume content>mineral powder content. There is a negative correlation between the compressive strength and permeability coefficient of the pervious concrete. Microscopic analysis shows that there are obvious pores in the microstructure of pervious concrete without silica fume or mineral powder. The addition of silica fume or mineral powder can effectively fill the pores, reduce the number of pores to a certain extent and improve the comprehensive performance of pervious concrete.

摘   要：采用超细水泥、抗裂防水剂、膨胀剂、减水剂等制备了大流动度高强超细水泥灌浆料，基于灰色关联度研究了各因素对灌浆料性能的影响，确定了灌浆料的最优配合比，并进行了微观结构分析。结果表明：采用最优配合比制备的灌浆料具有良好的工作性和力学性能，初始稠度为17.38 s，28 d抗压、抗折强度为95.7 MPa、15.9 MPa；56 d内灌浆料均表现为微膨胀；灌浆料的微观结构相对致密。 Abstract: A high fluidity, high strength, and ultra fine cement grouting material was prepared by using ultrafine cement, crack resistant and waterproof agents, expansion agents, and water reducing agents. The influence of various factors on the performance of the grouting material was studied based on grey relational analysis, and the optimal mix proportion of the grouting material was determined, and microstructure analysis was conducted. The results show that the grouting material prepared with the optimal mix proportion has good workability and mechanical properties, with an initial consistency of 17.38 s and 28 d compressive and flexural strength of 95.7 MPa and 15.9 MPa. The grouting material shows slight expansion within 56 d. The microstructure of the grouting material is relatively dense.

李彦江,冯月娥.基于灰色关联度的超细水泥灌浆料的制备与性能研究[J].混凝土与水泥制品,2024(2):11-14. LI Y J,FENG Y E.Preparation and performance study of ultrafine cement grouting materials based on grey relational analysis[J].China Concrete and Cement Products,2024(2):11-14.

摘   要：为了解决巴基斯坦废弃粉细砂抹灰砂浆易开裂、空鼓、脱落等问题，研究了纤维掺量（0、0.3、0.6、0.9、1.2、1.5 kg/m3）和膨胀剂掺量（0、4%、8%、12%、16%）对砂浆干燥收缩和弹性模量的影响。结果表明：随着纤维掺量的增加，砂浆的干燥收缩先降低后增加，弹性模量先增加后降低，纤维的最佳掺量为0.9 kg/m3；随着膨胀剂掺量的增加，砂浆的干燥收缩和弹性模量均降低；掺入适量的纤维和膨胀剂可以提高砂浆的耐久性能。 Abstract: To solve the problems of cracking, hollowing, and detachment of plastering mortar with waste fine sand from Pakistani, the effects of fiber contents(0, 0.3, 0.6, 0.9, 1.2, 1.5 kg/m3) and expansion agent contents(0、4%、8%、12%、16%) on the drying shrinkage and elastic modulus of mortar were studied. The results show that with the increase of fiber content, the drying shrinkage of mortar first decreases and then increases, and the elastic modulus first increases and then decreases. The optimal fiber content is 0.9 kg/m3. With the increase of expansion agent content, the drying shrinkage and elastic modulus of mortar decrease. Adding an appropriate content of fiber and expansion agent can improve the durability of mortar.

吴筱文,乌呢日,申和庆,等.巴基斯坦废弃粉细砂抹灰砂浆的耐久性能研究[J].混凝土与水泥制品,2024(2):15-17. WU X W,WU N R,SHEN H Q,et al.Study on the durability of plastering mortar with waste fine sand from Pakistani[J].China Concrete and Cement Products,2024(2):15-17.

摘   要：进行了高温作用后混凝土的单调拉伸和往复拉伸试验，分析了其主要力学特征参数（抗拉强度、初始弹性模量、峰值应变、残余应变、割线模量等）的温度效应和应变率效应。采用混凝土损伤模型，引入温度参数，提出了基于应变率效应和温度效应的混凝土加卸载模型，验证了模型的适用性。结果表明：混凝土的抗拉强度及初始弹性模量随着温度的升高而降低，峰值应变随着温度的升高而增大，残余应变累积与温度无关，而随应变率的增大而累积速率加快；混凝土卸载曲线的非线性程度与应变率呈正相关，与温度无明显关系；混凝土再加载曲线的非线性程度与温度呈正相关，与应变率无明显关系；通过对比得出，所提出的模型计算结果与实测结果吻合程度较好。 Abstract: The monotonic and reciprocating tensile tests of concrete after high temperature were carried out, and the temperature and strain rate effects of the main mechanical characteristic parameters of concrete (including tensile strength, initial elastic modulus, peak strain, residual strain, secant modulus, etc.) were analyzed. A concrete loading and unloading model based on strain rate effect and temperature effect was proposed by using the existing concrete damage model, and the applicability of the model was verified. The results show that the tensile strength and initial elastic modulus of concrete decrease with the increase of temperature. The peak strain increases with the increase of temperature, the accumulation of residual strain is independent of temperature, and the accumulation rate increases with the increase of strain rate. The nonlinearity of concrete unloading curve is positively related to strain rate, but has no obvious relationship with temperature. The nonlinearity of the concrete reloading curve is positively correlated with temperature, but has no obvious relationship with strain rate. By comparing the calculated results of the model with the measured results, the proposed model is in good agreement with the measured results.

蒋奇勇,陈平.高温作用后混凝土的动态轴拉力学性能研究[J].混凝土与水泥制品,2024(2):18-23,27. JIANG Q Y,CHEN P.Study on dynamic axial tensile properties of concrete subjected to high temperature[J].China Concrete and Cement Products,2024(2):18-23,27.

摘   要：研究了葡萄糖酸钠对掺减水剂水泥浆体流动度的影响，并通过测试减水剂在水泥颗粒表面的吸附率、水化产物含量、固体颗粒的比表面积，分析了葡萄糖酸钠对流动度的影响机理。结果表明：葡萄糖酸钠的掺入提高了水泥浆体的流动度，降低了减水剂的吸附率，抑制了水泥浆体中早期钙矾石生成，但加速了中期钙矾石的生成速率，使钙矾石总量提高；葡萄糖酸钠降低了水泥浆体早期的比表面积，但后期比表面积明显增加。 Abstract: The effect of sodium gluconate on the fluidity of cement slurry with polycarboxylate superplasticizer was studied, and the mechanism of its influence on fluidity was analyzed by testing the adsorption rate of polycarboxylate superplasticizer on the surface of cement particles, the content of hydration products, and the specific surface area of solid particles. The results show that the addition of sodium gluconate improves the fluidity of cement slurry, reduces the adsorption rate of polycarboxylate superplasticizer, inhibites the formation of ettringite in cement slurry in the early age, but accelerates the formation rate of ettringite in the midium age, resulting in an increase in the total amount of ettringite. Sodium gluconate reduces the specific surface area of cement slurry at early age, but the specific surface area significantly increases in the later age.

栗翔,毛永琳,张建纲,等.葡萄糖酸钠对水泥浆体流动度的影响及作用机理[J].混凝土与水泥制品,2024(2):24-27. LI X,MAO Y L,ZHANG J G,et al.Influence and mechanism of sodium gluconate on the fluidity of cement slurry[J].China Concrete and Cement Products,2024(2):24-27.