摘   要：通过加速劣化试验方法研究了超高性能混凝土（UHPC）在模拟海洋侵蚀环境下的力学和耐久性能。结果表明：海水养护下UHPC的力学性能受开始浸泡时间的影响较小，长期力学性能发展比较稳定；UHPC具有良好的适应性和耐久性能，冻融循环对UHPC性能的影响相对较大，但介质类型对其性能的影响较小；随着硫酸盐干湿循环次数的增加，UHPC的相对动弹性模量和抗压强度耐蚀系数先增加后降低，质量损失增加；硫酸盐干湿循环会导致UHPC表面露出的钢纤维锈蚀，但内部结构无损伤，钢纤维与基体结合紧密。 Abstract: The mechanical properties and durability of ultra-high performance concrete(UHPC) under marine environment were investigated by accelerated deterioration test. The results show that the mechanical properties of UHPC under seawater curing are less affected by the initial immersion time, and the long-term mechanical properties are relatively stable. UHPC has good adaptability and durability. Freeze-thaw cycles have a relatively large effect on UHPC performance, but media type has less effect on UHPC performance. With the increase of the number of dry and wet cycles of sulfate, the relative dynamic elastic modulus and compressive strength corrosion resistance coefficient of UHPC first increase and then decrease, and the mass loss increases. The dry and wet cycles of sulfate lead to steel fiber corrosion on the surface, but the internal structure is not damaged, and the steel fiber is closely combined with the matrix.

张志豪,陈露一,黄有强,等.海洋侵蚀环境下超高性能混凝土的力学与耐久性能研究[J].混凝土与水泥制品,2022(7):1-4,9. ZHANG Z H,CHEN L Y,HUANG Y Q,et al.Study on Mechanical Proporties and Durability of Ultra-high Performance Concrete Under Marine Erosion Environment[J].China Concrete and Cement Products,2022(7):1-4,9.

摘   要：采用普通硅酸盐水泥、气凝胶粉、石墨改性EPS颗粒、发泡剂等制备了干密度约为120 kg/m3的石墨改性EPS颗粒超轻泡沫混凝土，研究了石墨改性EPS颗粒对其密度、力学性能、吸水率、导热系数和孔结构的影响。结果表明：当石墨改性EPS颗粒掺量为30%时，超轻泡沫混凝土的各项性能最优，抗压强度为0.25 MPa，吸水率为10.3%，导热系数为0.032 6 W/(m·K)；随着石墨改性EPS颗粒掺量的增加，损泡率明显增大，孔径分布和孔结构参数发生明显改变。 Abstract: The foam concrete with a dry density of 120 kg/m3 was prepared by ordinary portland cement, aerogel powder, graphite modified EPS particles, foaming agent and additive. The effects of graphite modified EPS particles content on the density, mechanical properties, water absorption, thermal conductivity, and pore structure of foam concrete were studied. The results show that when graphite modified EPS particles with the content of 30% are added, the foam concrete has the best properties, the compressive strength is 0.25 MPa, the water absorption is 10.3%, and the thermal conductivity is 0.032 6 W/(m·K). With the increase of the content of graphite modified EPS particles, the bubble loss rates increase obviously, and the pore size distribution and pore structure parameters change obviously.

康升荣,程宝军,麻鹏飞,等.石墨改性EPS颗粒对超轻泡沫混凝土性能的影响[J].混凝土与水泥制品,2022(7):5-9. KANG S R,CHENG B J,MA P F,et al.Influence of Graphite Modified EPS Particles on the Performance of Ultra-light Foam Concrete[J].China Concrete and Cement Products,2022(7):5-9.

李继存,赵少鹏,陆加越,等.超缓释降黏型外加剂在泵送顶升自密实混凝土中的应用[J].混凝土与水泥制品,2022(7):10-13,19. LI J C,ZHAO S P, LU J Y,et al.Application of Super Slow-release Viscosity-reducing Admixture in Pumping-up Self-compacting Concrete[J].China Concrete and Cement Products,2022(7):10-13,19.

摘   要：利用铁尾矿砂制备了超高性能混凝土（UHPC），研究了在高温环境下不同胶砂比（1∶0.8、1∶0.9、1:1.0、1∶1.1）对UHPC试件力学性能的影响，测定了高温下UHPC的孔结构，并用SEM表征了UHPC的微观结构，探讨了胶砂比对UHPC高温性能影响的机理。结果表明，随着温度的不断升高，不同胶砂比的UHPC力学性能出现了不同程度的下降，其中，胶砂比为1∶1.0的UHPC在各个目标温度下均表现出相对较高的力学性能；微观分析表明胶砂比为1∶1.0的UHPC基体比胶砂比为1∶0.8的UHPC基体更加密实，在高温作用下裂缝宽度更小，且基体与钢纤维的结合能力更强，有效降低了钢纤维在高温下的破坏程度。 Abstract: Ultra-high performance concrete(UHPC) was prepared by iron tailings sand. The effect of different binder-sand ratio(1∶0.8, 1∶0.9, 1∶1.0, 1∶1.1) on the mechanical properties of UHPC at high temperature was studied. The pore structure of UHPC at high temperature was determined. The microstructure of UHPC was charactered by SEM, and the mechanism of the effect of binder-sand ratio on the high temperature properties of UHPC was discussed. The results show that with the increase of temperature, the mechanical properties of UHPC with different binder-sand ratio decrease in varying degrees, and the UHPC with 1∶1.0 binder-sand ratio shows relatively high mechanical properties at each target temperature. Pore structure and SEM analysis show that UHPC matrix with 1∶1.0 binder-sand ratio is denser than UHPC matrix with 1∶0.8 binder-sand ratio, and crack width is smaller under high temperature. In addition, UHPC matrix with 1∶1.0 binder-sand ratio has stronger bonding ability with steel fiber, which effectively reduces the damage degree of steel fiber at high temperature.

王宏,王丹丹,朱平,等.胶砂比对UHPC高温力学性能及微观结构的影响[J].混凝土与水泥制品,2022(7):14-19. WANG H,WANG D D,ZHU P,et al.Effect of Binder-sand Ratio on High-temperature Mechanical Properties and Microstructure of UHPC[J].China Concrete and Cement Products,2022(7):14-19.

摘   要：为了修复机场混凝土道面微裂缝，采用液相溶胶-凝胶法合成了一种硅聚集体纳米修复材料，并研究了该纳米修复材料对道面混凝土抗压、抗折、防水、抗渗、抗氯离子渗透、抗冻、耐磨等性能的改善效果，探讨了其修复机理。结果表明：经纳米材料修复后，含微裂缝混凝土的抗压强度提高了1.1倍，抗折强度提高了90%，抗渗性能提高了1.6倍，抗氯离子渗透性能提高了60%，抗冻性能提高了70%，耐磨性能提高了65%，防水性能有显著改善，摩擦系数变化不大。 Abstract: To repair the micro-cracks in the concrete pavement of the airport, a silicon aggregate nano-repair material was synthesized by liquid sol-gel method. The improvement effects of nano-repair material on the properties of pavement concrete such as compressive strength, flexural strength, waterproofing, impermeability, chloride ion penetration resistance, freeze-thaw resistance and wear resistance were studied, and its repair mechanism was discussed. The results show that the compressive strength, flexural strength, impermeability, chloride ion penetration, freeze-thaw resistance and wear resistance  of concrete with micro-cracks are increased by 1.1 times, 90%, 1.6 times, 60%, 70% and 65%, respectively. The waterproof performance is significantly improved, and the surface friction coefficient has not changed much.

王后裕,方新宇,刘海涛,等.纳米材料修复混凝土道面微裂缝的研究[J].混凝土与水泥制品,2022(7):20-24. WANG H Y,FANG X Y,LIU H T,et al.Study on Micro-cracks Repairing of Concrete Pavement with Nano-repair Materials[J].China Concrete and Cement Products,2022(7):20-24.

摘   要：考虑混凝土单轴受压破坏机理，在混凝土静力损伤基础上引入弹簧-摩擦块模型，以模拟混凝土弹塑性阶段的细观结构变化。基于细观模型中弹簧、摩擦块对混凝土断裂面的影响，分析了混凝土受压损伤的破坏规律，建立了不同强度等级混凝土弹塑性单轴受压损伤本构模型，采用混凝土分形曲面模拟方法对所建模型进行了验证。结果表明：所建立的模型能够较好描述混凝土的塑性变形，对混凝土弹塑性的离散范围具有良好的预测能力。 Abstract: Considering the failure mechanism of concrete under uniaxial compression, on the basis of concrete static damage, a spring-friction block model was introduced to simulate the meso-structural changes of concrete in the elastic-plastic stage. Based on the influence of the spring and friction block on the fracture surface of concrete in the mesoscopic model, the failure law of concrete compressive damage was analyzed, and the elastic-plastic uniaxial compressive damage constitutive model of concrete with different strength grades was established. The model was verified by the concrete fractal surface simulation method. The results show that the established model can describe the impact of concrete plastic deformation well, and has a good ability to predict the elastoplastic dispersion range of concrete.

谢明,汪鹏,郑山锁,等.混凝土弹塑性单轴受压分形损伤本构关系研究[J].混凝土与水泥制品,2022(7):25-29,39. XIE M,WANG P,ZHENG S S,et al.Fractal Damage Constitutive Relation of Concrete Elastoplastic Uniaxial Compression[J].China Concrete and Cement Products,2022(7):25-29,39.