摘   要：为研究矿物掺合料对泡沫混凝土力学性能、导热系数、抗冻性的影响，以粉煤灰掺量10%的泡沫混凝土为基准，通过分别单掺硅灰和矿粉及复掺硅灰、矿粉研究了矿物掺合料对泡沫混凝土性能的改善作用。结果表明：当分别单掺硅灰和矿粉时，泡沫混凝土的抗压强度、抗折强度及抗冻性均得到一定提升，导热系数随之增大；当复掺硅灰和矿粉，且复掺比例为2∶1时，泡沫混凝土的强度和抗冻性最佳，导热系数最大。 Abstract: To study the influence of mineral admixtures on the mechanical properties, thermal conductivity, and frost resistance of foamed concrete, based on the foamed concrete with a fly ash content of 10%, by mixing silica fume and mineral powder alone and compounding silica fume and mineral powder respectively, the improvement effect of mineral admixture on the foamed concrete was studied. The results show that when silica fume and mineral powder are added separately, the compressive strength, flexural strength and frost resistance of foamed concrete are improved to a certain extent, and the thermal conductivity increases accordingly. When silica fume and mineral powder are added, the compressive strength, flexural strength, and frost resistance of foamed concrete are increased. When the mixing ratio of silica fume and slag powder is 2∶1, the strength and frost resistance of the foamed concrete are the best, and the thermal conductivity is the largest.

刘召超.多元矿物掺合料对泡沫混凝土性能影响研究[J].混凝土与水泥制品,2021(8):1-4. LIU Z C.Effect of Multi-mineral Admixtures on Properties of Foamed Concrete[J].CHINA CONCRETE AND CEMENT PRODUCTS,2021(8):1-4.

摘   要：选择三种养护方式（标准养护、80 ℃热水养护、洒水养护）、设置5种碳纳米管掺量（0、0.05%、0.10%、0.15%、0.20%），研究了碳纳米管的分散性和掺量、养护方式对碳纳米管活性粉末混凝土力学性能的影响，并基于SEM测试结果对基体进行了微观分析。结果表明：经分散处理后的MWCNTs溶液的分散性和稳定性提高；相较于未分散处理的MWCNTs，MWCNTs分散液对活性粉末混凝土抗压、抗折强度的提高幅度更大；80 ℃热水养护下，当经分散处理后的MWCNTs掺量为0.10%时，MWCNTs活性粉末混凝土的抗压和抗折强度最大；标准养护和洒水养护下，当经分散处理后的MWCNTs掺量为0.15%时，MWCNTs活性粉末混凝土的抗压和抗折强度最大；SEM结果显示，胶凝材料二次水化生成了大量水化硅酸钙，减少了孔隙；碳纳米管能与基体紧密连接，阻止微裂缝的生成和扩展，起到了桥接和填充作用。 Abstract: Three kinds of curing methods(standard curing, 80 ℃ hot water curing and sprinkling curing) were selected, 5 kinds of carbon nanotube(MWCNTs) content(0, 0.05%, 0.10%, 0.15%, 0.20%)were set, the influence of the dispersibility and dosage of MWCNTs and curing methods on the mechanical properties of carbon nanotube reactive powder concrete was studied. The microstructure of matrix was characterized by SEM. The results show that the dispersion and stability of the MWCNTs solution after dispersion treatment are improved. Compared with the undispersed MWCNTs, the MWCNTs dispersion has a greater improvement in the compressive and flexural strength of reactive powder concrete. Under 80 ℃ hot water curing, when the content of dispersed MWCNTs is 0.10%, the compressive and flexural strength of MWCNTs reactive powder concrete reach the maximum. Under standard curing and sprinkling curtain curing, when the content of dispersed MWCNTs is 0.15%, the compressive and flexural strength of MWCNTs reactive powder concrete reach the maximum. SEM results show that the secondary hydration of the cementitious material produces a large amount of hydrated calcium silicate, which reduces porosity. MWCNTs can be closely connected with the matrix, preventing the formation and expansion of micro-cracks, and playing the role of bridging and filling.  

刘桂凤,朱鼎,陈正发,等.碳纳米管活性粉末混凝土力学性能试验研究[J].混凝土与水泥制品,2021(8):5-9. LIU G F,ZHU D,CHEN Z F,et al.Experimental Study on Mechanical Properties of Carbon Nanotube Reactive Powder Concrete[J].CHINA CONCRETE AND CEMENT PRODUCTS,2021(8):5-9.

摘   要：对比研究了不同掺量的高吸水树脂（SAP）与钙质膨胀剂（UEA）复合作用对低水灰比玻璃纤维增强水泥基材料（GRC）力学性能、收缩性能和抗裂性能的影响，并对抑制收缩机理进行了讨论。结果表明：预吸水的SAP释水具有内养护的效果，能够促进水泥水化；掺入0.2%的SAP能够提高水泥砂浆的力学性能，但是SAP含量进一步增加时，释水留下的孔隙会导致力学性能降低；SAP释放的水分能够补偿混凝土的内部湿度，从而降低毛细管张力，同时释放的水分能够提供给UEA进行膨胀反应，从而协同抑制水泥砂浆的收缩，细化裂缝，降低开裂指数，提高抗裂性能。 Abstract: The influence of super absorbent polymer(SAP) and calcium expansion agent (UEA) on mechanical properties, shrinkage properties and crack resistance of glass fiber reinforced cement（GRC） with low W/C was analyzed, and the mechanism of inhibiting shrinkage was also discussed. The results show that the pre-absorbed SAP release water has the effect of internal curing and can promote the hydration of cement. The addition of 0.2% SAP can improve the mechanical properties of cement mortar. However, when the SAP content increases continuously, the pores left by the release of water further will cause decrease in mechanical properties. The water released by SAP can compensate the internal humidity of the concrete, thereby reducing the capillary tension. On the other hand, the released water can be provided to UEA for expansion reaction, thereby synergistically inhibiting the shrinkage of cement mortar, thinning cracks, reducing the cracking index, and having a better cracking resistance.

安雪玮,邹闻达,汪金能.膨胀剂和高吸水树脂对低水灰比GRC性能的影响[J].混凝土与水泥制品,2021(8):10-13. AN X W,ZOU W D,WANG J N.Influence of Expansive Agent and Super Absorbent Polymer on the Performance of GRC with Low Water-cement Ratio[J].CHINA CONCRETE AND CEMENT PRODUCTS,2021(8):10-13.

摘   要：研究了羟丙基甲基纤维素（HPMC）溶液浓度与黏度的关系和HPMC溶液黏度与其透水混凝土性能的关系，得出了满足力学性能及透水性能要求的HPMC透水混凝土施工温度条件。结果表明：HPMC溶液黏度随浓度增大而增加；HPMC透水混凝土的抗压强度随溶液黏度增加先增后减，在满足抗压强度要求的黏度区间内，其抗折强度及透水性均满足要求；在一定条件下，HPMC黏度随温度升高而减小，对具有较高黏度的HPMC透水混凝土，可通过控制其拌合物的出机温度以满足和易性要求。 Abstract: The relationship between the concentration and viscosity of HPMC, viscosity of HPMC solution permeability of concrete was studied. The temperature condition of HPMC permeable concrete construction that meet the requirements of mechanical performance and water permeability was obtained. The results show that the viscosity of HPMC solution increases with the increase of concentration. The compressive strength of HPMC permeable concrete increases first and then decreases with the increase of solution viscosity. Within the viscosity range that meets the requirements of compressive strength, its flexural strength and water permeability meet the requirements. Within the certain conditions, the HPMC viscosity decreases with the increase of temperature. For HPMC permeable concrete with higher viscosity, the exit temperature of the mixture can be controlled to ensure that the construction operation and workability are satisfied.

高梦秋,苏悦,杨航.黏度对HPMC透水混凝土性能及施工温度的影响[J].混凝土与水泥制品,2021(8):14-18. GAO M Q,SU Y,YANG H.The Effect of Viscosity on the Performance and Construction Temperature of HPMC Permeable Concrete[J].CHINA CONCRETE AND CEMENT PRODUCTS,2021(8):14-18.

摘   要：设计了四种干湿比(1∶1、3∶1、5∶1、7∶1)和两种干燥方式(烘箱干燥、自然干燥)，通过相对抗压强度和相对动弹性模量的变化研究了干湿循环下硫酸盐侵蚀混凝土的力学性能劣化规律，并利用扫描电子显微镜、X射线衍射仪和压汞仪探究了微观结构的演变过程。结果表明：硫酸盐侵蚀混凝土的力学性能呈现先增加后降低的趋势；烘箱干燥和自然干燥下，混凝土劣化相对较严重的干湿比分别为3∶1和5∶1；混凝土孔隙总体积随龄期的延长不断降低，其中，有害孔（50 nm≤d≤200 nm）的减少是孔隙细化的最主要原因。 Abstract: Four dry-wet ratios (1∶1, 3∶1, 5∶1, 7∶1) and two drying methods(oven drying, natural drying)were designed. Base on the change rules of relative compressive strength and relative dynamic elasticity modulus, the degradation law of sulfate attacked concrete performance in alternating drying-wetting environments was studied, and the evolution of the microstructure was explored by scanning electron microscope, X-ray diffractometer and mercury porosimeter. The results show that the mechanical properties of sulfate attacked concrete show a trend of first increasing and then decreasing. Under oven-drying and air-drying, the dry-wet ratios for the relatively serious deterioration of concrete are 3∶1 and 5∶1 respectively. The total volume of concrete pores continues to decrease with erosion. The reduction of harmful pores(50 nm≤d≤200 nm) is the main reason for pore refinement.

郭进军,王锟,陈坤鹏,等.基于硫酸盐侵蚀的混凝土干湿循环制度研究[J].混凝土与水泥制品,2021(8):19-23,27. GUO J J,WANG K,CHEN K P,et al.Research on Dry-wet Cycle System of Concrete Under Sulfate Attack[J].CHINA CONCRETE AND CEMENT PRODUCTS,2021(8):19-23,27.

摘   要：研究了掺加MgO膨胀剂配制的补偿收缩混凝土在具有高抗裂性要求的大体积混凝土侧墙施工过程中的体积变形和温度变化情况。现场试验结果表明：掺加6.2%M型MgO膨胀剂的C35补偿收缩混凝土在满足强度发展要求的前提下，可以在大体积混凝土结构内部温度下降段产生一定的膨胀，并长期保持稳定，补偿混凝土结构的温度收缩，从而使结构内部产生少量的预压应力，降低混凝土结构收缩裂缝的出现几率。 Abstract: The temperature and volume variation of shrinkage-compensating concrete mixed with MgO expansive agent was measured during the construction of a mass concrete wall with high anti-cracking requirement. The results show that MgO expansive agent compensates the shrinkage of mass concrete effectively during the descending period of temperature. The ultimate volumetric expansive rate of concrete is positive, forming a compressive pre-stress to resist cracking of concrete effectively.

曹丰泽,高玉亭,张慧杰,等.MgO膨胀剂在大体积混凝土结构中的抗裂效果研究[J].混凝土与水泥制品,2021(8):24-27. CAO F Z,GAO Y T,ZHANG H J,et al.Study on the Anti-cracking Efficiency of MgO Expansive Agent on Shrinkage-compensating Concrete in Mass Concrete Wall Structure[J].CHINA CONCRETE AND CEMENT PRODUCTS,2021(8):24-27.