摘   要：分别用三乙醇铝和三乙醇铁通过原位水解法制备了纳米Al2O3和纳米Fe2O3分散液，并用四臂聚乙二醇丙烯酰胺酯、丙烯酸、甲基丙烯酸乙二醇磷酸酯和乙烯基咪唑通过自由基聚合制备了两性聚合物分散剂（APD），再将纳米Al2O3、纳米Fe2O3分散液和氧化石墨烯（GO）分散液与APD复合制备了混凝土抗干缩剂（AFG），并对AFG的分子结构及性能进行了研究。结果表明：APD能够吸附纳米Al2O3、Fe2O3与GO在分子链上使其均匀分散在水相及水泥基体中；将AFG掺入混凝土中能够显著提高混凝土的强度、抗渗及抗干缩性能。 Abstract: Nano Al2O3 and nano Fe2O3 dispersions were prepared by in-situ hydrolysis of aluminum triethanol and iron triethanol, respectively. Amphoteric polymer dispersions(APD) were prepared by radical polymerization of four arm polyethylene glycol acrylamide, acrylic acid, ethylene glycol methacrylate phosphate and vinyl imidazole. The anti shrinkage admixture(AFG) for concrete was prepared by compounding nano Al2O3 and Fe2O3 dispersion, graphene oxide (GO) dispersion with APD. The molecular structure and properties of AFG were studied. The results show that APD can adsorb nano Al2O3, Fe2O3 and GO on the molecular chain to make them uniformly disperse in the aqueous phase and cement matrix. Adding AFG into concrete can significantly improve the strength, impermeability and shrinkage resistance of concrete.

贾君,吕生华,任洋军,等.混凝土抗干缩剂的制备及性能研究[J].混凝土与水泥制品,2023(4):1-5. JIA J,LYU S H,REN Y J,et al.Study on Preparation and Properties of Concrete Anti Shrinkage Admixture[J].China Concrete and Cement Products,2023(4):1-5.

摘   要：为了研究碳纳米管（CNTs）在超高性能混凝土（UHPC）中的分散效果及其对UHPC力学性能的影响，进行了不同CNTs掺量UHPC的动力黏度、抗压强度和抗折强度试验。结果表明：CNTs在UHPC基体中的分散效果随着CNTs掺量的增加而不断变差，且会导致较高CNTs掺量的UHPC力学性能降低；当CNTs掺量为0.1%时，CNTs增强UHPC的力学性能最佳。 Abstract: In order to study the dispersion effect of carbon nanotubes(CNTs) in ultra-high performance concrete (UHPC) and its influence on the mechanical properties of UHPC, shear viscosity, compressive strength and flexural strength of UHPC with different CNTs content were tested. The results show that the dispersion effect of CNTs in UHPC matrix deteriorates with the increase of CNTs content, and the mechanical properties of UHPC decrease with the increase of CNTs content. When the CNTs content is 0.1%, the mechanical properties of UHPC are the best.

成芳,李小明,黄政宇.碳纳米管在UHPC中的分散效果及对UHPC力学性能的影响[J].混凝土与水泥制品,2023(4):6-8,29. CHENG F,LI X M,HUANG Z Y.Dispersion Effect of Carbon Nanotubes in UHPC and Its Influence on Mechanical Properties of UHPC[J].China Concrete and Cement Products,2023(4):6-8,29.

摘   要：为了研究辅助振捣对自密实重晶石混凝土离析的影响，以振捣棒电压（70 V、85 V、100 V）、振捣时间（6 s、8 s、10 s）及插入深度（100 mm、200 mm、300 mm）三个因素设计了正交试验。在内径和深度均为300 mm的检测筒内进行分层离析试验，试验采用两种辅助振捣方式（第一种插拔静止状态下的振捣棒、第二种插拔振动状态下的振捣棒），并对结果进行了评价与分析。结果表明：采用第一种振捣方式时，电压70 V、振捣时间6 s、插入深度200 mm为最优振捣参数，自密实重晶石混凝土的离析最小；不同粒径粗骨料的离析有明显区别，粗骨料粒径越大，离析越大；采用相同振捣参数，第二种振捣方式比第一种振捣方式下的自密实重晶石混凝土离析更大。 Abstract: In order to study the effect of auxiliary vibration on segregation of self-compacting barite concrete, the orthogonal experiment was designed from three factors of poker vibrator voltages (70 V, 85 V, 100 V), vibration time (6 s, 8 s, 10 s) and vibration depths (100 mm, 200 mm, 300 mm). The segregation test was carried out in three layers of mold with inner diameter and depth of 300 mm, and the results were analyzed and evaluated. Two methods of auxiliary vibration (the first method is keeping poker vibrator in static state when it is inserted and pulled and the second is in vibrating state) were adopted in the test. The results show that the optimal vibration parameters are voltage of 70 V, vibration time of 6 s and insertion depth of 200 mm when the first vibration method is adopted, and the segregation of self-compacting barite concrete is the smallest. The separation of coarse aggregates with different particle sizes has an apparent difference, and the larger the particle size of the aggregate, the greater the segregation. With the same vibration parameters, the segregation of self-compacting barite concrete in the second vibration method is greater than that in the first vibration method.

石建军,李竹静,张志恒,等.辅助振捣对自密实重晶石混凝土离析的影响[J].混凝土与水泥制品,2023(4):9-13. SHI J J,LI Z J,ZHANG Z H,et al.Effect of Auxiliary Vibration on Segregation of Self-Compacting Barite Concrete[J].China Concrete and Cement Products,2023(4):9-13.

摘   要：由无机纳米材料、有机高分子材料等多种外加剂制备了一种新型悬浮稳定剂，通过单因素试验研究了该悬浮稳定剂对水泥基自流平砂浆的工作性、强度、收缩性能、稳定性的影响，并得到了最佳掺量。此外，还对比了悬浮稳定剂和纤维素醚在自流平砂浆中的使用效果。结果表明：所制备的悬浮稳定剂可以取代纤维素醚，降低了自流平砂浆的用水量敏感度，提高了自流平砂浆的后期强度，硬化后收缩率稳定，减小了开裂风险，使用效果比纤维素醚更优。 Abstract: A new suspension stabilizer was prepared from inorganic nano materials, organic polymer materials and other additives. The influence of the suspension stabilizer on the workability, strength, shrinkage and stability of cement-based self leveling mortar was studied through single factor test, and the best dosage was obtained. In addition, the effects of suspension stabilizer and cellulose ether in self leveling mortar were compared. The results show that the prepared suspension stabilizer can replace cellulose ether, reduce the water volume sensitivity of self leveling mortar, improve the late strength, stabilize the shrinkage rate after hardening, reduce the risk of cracking, and the use effect is better than cellulose ether.

逄鲁峰,黄凌苗,杜诗寒,等.自制悬浮稳定剂对水泥基自流平砂浆性能的影响[J].混凝土与水泥制品,2023(4):14-17. PANG L F,HUANG L M,DU S H,et al.Effect of Self-made Suspension Stabilizer on Properties of Cement-Based Self Leveling Mortar[J].China Concrete and Cement Products,2023(4):14-17.

摘   要：研究了石灰石粉的细度（18、38、75 μm）和掺量（10%、20%、30%）对清水混凝土性能和外观质量的影响。结果表明：随着石灰石粉掺量的增加，清水混凝土的抗压强度基本呈降低趋势，提高石灰石粉的细度可以减轻石灰石粉对抗压强度的不利影响；与细度为18 μm、75 μm的石灰石粉相比，细度为38 μm的石灰石粉可以改善新拌清水混凝土的初始气泡结构，推动新拌清水混凝土中的微细气泡向大气泡转变；石灰石粉不利于硬化清水混凝土表面气孔结构的优化，但适量（10%）石灰石粉能够有效降低硬化清水混凝土表面的气孔含量；石灰石粉可以改善清水混凝土的表面色差，改善程度与石灰石粉的细度和掺量呈正相关；石灰石粉有助于降低清水混凝土的表面粗糙度，但当石灰石粉的细度超过38 μm或者掺量大于20%时，表面粗糙度几乎不再降低；工程应用结果表明，选用细度为38 μm或18 μm的石灰石粉并控制其掺量为10%，可以制备出性能和外观质量满足要求的清水混凝土构件。 Abstract: The influence of the fineness(18, 38, 75 μm) and content(10%, 20%, 30%) of limestone powder on the performance and appearance quality of fair-faced concrete was studied. The results show that with the increase of limestone powder content, the compressive strength of fair-faced concrete decreases, but increasing the fineness of limestone powder can reduce the adverse impact of limestone powder on compressive strength. Compared with limestone powder with fineness of 18 μm and 75 μm, the limestone powder with fineness of 38 μm can improve the initial air bubble structure of fresh fair-faced concrete and promote the transformation of micro air bubbles into large air bubbles in fresh fair-faced concrete. Limestone powder is not conducive to the optimization of pore structure on hardened fair-faced concrete surface, but an appropriate content (10%) of limestone powder can effectively reduce the pore content on hardened fair-faced concrete surface. Limestone powder can improve the surface color difference of fair-faced concrete, and the improvement degree is positively related to the fineness and content of limestone powder. Limestone powder can help to reduce the surface roughness of fair-faced concrete, but when the fineness of limestone powder is more than 38 μm or the content is more than 20%, the surface roughness will hardly decrease. The engineering application results show that fair-faced concrete components with performance and appearance quality meeting the requirements can be prepared by selecting limestone powder with fineness of 38 μm or 18 μm and controlling its content to 10%.

陈光伟,安景峰,郭赵元,等.石灰石粉对清水混凝土性能和外观质量的影响[J].混凝土与水泥制品,2023(4):18-23. CHEN G W,AN J F,GUO Z Y,et al.Influence of Limestone Powder on Performance and Appearance Quality of Fair-Faced Concrete[J].China Concrete and Cement Products,2023(4):18-23.

摘   要：介绍了近年来国内外关于杂散电流腐蚀混凝土和机制砂混凝土的研究现状，分析了杂散电流引发钢筋腐蚀的机理，介绍了杂散电流对混凝土耐久性能造成的影响，总结了在母岩种类、石粉含量等因素控制下机制砂混凝土性能的差异，指出了当严格把控机制砂的母岩和石粉含量时，机制砂混凝土具备良好的抗氯离子侵蚀性能，能够作为天然砂混凝土的替代品，并对机制砂混凝土抗杂散电流腐蚀在地铁管片工程中的应用进行了展望。 Abstract: The research status of stray current corrosion concrete and manufactured sand concrete at home and abroad in recent years is introduced. The mechanism of steel bar corrosion caused by stray current is analyzed. The effect of stray current on durability of concrete is introduced, and the difference of performance of manufactured sand concrete under the control of factors such as parent rock type, stone powder content is summarized. It is pointed out that when the content of parent rock and stone powder of manufactured sand is strictly controlled, manufactured sand concrete has good chloride ion corrosion resistance and can be used as a substitute for natural sand concrete. The application of manufactured sand concrete against stray current corrosion in subway segment engineering is prospected.

金凡,张苑竹.地铁杂散电流对钢筋混凝土的腐蚀研究综述及机制砂应用展望[J].混凝土与水泥制品,2023(4):24-29. JIN F,ZHANG Y Z.Summary of Research on Corrosion of Reinforced Concrete Caused by Stray Current in Subway and Application Prospect of Manufactured Sand[J].China Concrete and Cement Products,2023(4):24-29.