摘   要：研究了混凝土配合比中骨料的相关问题。结果表明：混凝土中的骨料可分为天然骨料、机制骨料、废弃物骨料和人造骨料；不同国家的混凝土配合比设计方法步骤不同，我国配合比设计方法中缺乏对骨料级配的模型化计算方法；Talbol通式和Dinger-Funk方程均可用于计算混凝土的骨料级配，当分布指数在0.45~0.50时，C40混凝土的工作性和抗压强度最优；砂石骨料一体化设计获得的级配并不适用于所有强度等级的混凝土，不同分布指数下的骨料级配理论曲线需要考虑其适用的强度等级范围。 Abstract: The related issues of aggregates in concrete mix proportions were studied. The results indicate that aggregates in concrete can be divided into natural aggregates, manufactured aggregates, waste aggregates, and artificial aggregates. The design methods and steps for concrete mix proportions vary in different countries, and there is a lack of modeling calculation methods for aggregate gradation in Chinese mix proportion design methods. Both the Talbol formula and the Dinger-Funk equation can be used to calculate the aggregate gradation of concrete. When the distribution index is between 0.45 and 0.50, the workability and compressive strength of C40 concrete are optimal. The gradation obtained from the integrated design of sand and gravel aggregates is not applicable to all strength grades of concrete. The theoretical curve of aggregate gradation under different distribution indices needs to consider the range of strength grades it is suitable for.

王军,李曦,徐芬莲,等.混凝土配合比设计中的骨料问题研究[J].混凝土与水泥制品,2024(9):1-6,12. WANG J,LI X,XU F L,et al.Research on aggregate issues in concrete mix proportion design[J].China Concrete and Cement Products,2024(9):1-6,12.

摘   要：为了研究新拌混凝土不均匀性对硬化性能的影响，制备了坍落度在130~260 mm的大流动度C50混凝土，通过砂率、矿物掺合料掺量和减水剂掺量调节混凝土的流动性，取不同部位（中心、边缘）混凝土测试工作性、力学性能、渗透性能等。结果表明：当中心、边缘混凝土骨料离析率组间变异系数不超过5%时，对混凝土的力学性能无明显影响；随着骨料离析率组间变异系数的增加，混凝土力学性能降低；同组间对比时，各组边缘混凝土的氯离子扩散系数、气体渗透系数均高于中心混凝土，中心混凝土的孔隙率较低，有害级孔和多害级孔占比低于边缘混凝土，中心、边缘混凝土的骨料离析率和水胶比组间变异系数较大的组别，孔径分布及孔隙率的差值也较大，氯离子扩散系数和气体渗透系数的差值也较大；总体上，新拌混凝土越均匀，硬化后的综合性能越好。 Abstract: In order to study the effect of inhomogeneity of fresh concrete on its hardened performance, high fluidity C50 concrete with a slump of 130~260 mm was prepared. The fluidity of the concrete was adjusted by sand ratio, mineral admixture content, and polycarboxylate superplasticizer content. Different parts(center, edge) of the concrete were tested for workability, mechanical properties, permeability, etc. The results show that when the coefficient of variation between the segregation rate groups of the center and edge concrete aggregates does not exceed 5%, it has no significant effect on the mechanical properties of concrete. As the coefficient of variation between the segregation rate groups increases, the mechanical properties of concrete decrease. When comparing within the same group, the chloride ion diffusion coefficient and gas permeability coefficient of the edge concrete in each group are higher than those of the center concrete. The porosity of the center concrete is lower, and the proportion of harmful and multi harmful pores is lower than those of the edge concrete. The groups with larger inter group variation coefficients of aggregate segregation rate and water binder ratio in the center and edge concrete also have larger differences in pore size distribution and porosity, and larger differences in chloride ion diffusion coefficient and gas permeability coefficient. Overall, the more uniform the freshly mixed concrete, the better its comprehensive performance after hardening.

刘强,庞超明,罗时勇,等.混凝土不均匀性的表征及其对硬化性能的影响[J].混凝土与水泥制品,2024(9):7-12. LIU Q,PANG C M,LUO S Y,et al.Characterization of concrete inhomogeneity and its influence on the hardened concrete properties[J].China Concrete and Cement Products ,2024(9):7-12.

摘   要：采用正交试验法研究了稀释剂、增韧剂、胶砂比对高强环氧灌浆料的流动度、强度的影响，并研究了2种固化剂掺入比例对高强环氧灌浆料性能的影响。结果表明：稀释剂对环氧灌浆料的流动度影响较大，稀释剂和增韧剂对环氧灌浆料的抗压强度影响较大，但三者对抗折强度影响相对较小；综合考虑工作性和力学性能，建议环氧灌浆料中稀释剂和增韧剂总掺量控制在5%~15%，胶砂比控制在0.35~0.45，且环氧灌浆料的流动度应控制在265 mm以下；固化剂合理复配可以提高环氧灌浆料的流动度，降低反应放热温度，有效控制反应速度，且不会影响环氧灌浆料的后期抗压强度。 Abstract: The influence of diluent, toughening agent, and binder-sand ratio on the fluidity and strength of high strength epoxy grouting material was studied using orthogonal experimental method, and the influence of the blending ratio of two curing agents on the properties of high-strength epoxy grouting material was studied. The results indicate that diluents have a significant impact on the fluidity of epoxy grouting materials, while diluents and toughening agents have a significant impact on the compressive strength of epoxy grouting materials, but their impact on flexural strength is relatively small. Taking into account both workability and mechanical properties, it is recommended to control the total content of diluent and toughening agent in epoxy grouting material between 5% and 15%, the binder-sand ratio between 0.35 and 0.45, and the fluidity of epoxy grouting material should be controlled below 265 mm. Reasonable compounding of curing agents can improve the fluidity of epoxy grouting materials, reduce the exothermic temperature, effectively control the reaction rate, and will not affect the late compressive strength of epoxy grouting material.  

李龙梓,彭先兵,孙静娴,等.材料组份对高强环氧灌浆料性能影响研究[J].混凝土与水泥制品,2024(9):13-16. LI L Z,PENG X B,SUN J X,Research on the impact of material components on the performance of high strength epoxy grouting materials[J].China Concrete and Cement Products ,2024(9):13-16.

摘   要：为了更精确地对混凝土抗压强度进行预测，以水泥、炉渣、粉煤灰、水、减水剂、粗骨料、细骨料、龄期作为混凝土强度预测指标，运用CRITIC算法对指标进行了加权处理，在此基础上，引入新的机器学习算法轻量级梯度提升机（LightGBM）对样本进行了计算训练，同时，运用K-10折交叉验证方式对模型参数进行了优化，最终建立了CRITIC-LightGBM混凝土抗压强度预测模型。运用该模型对混凝土的抗压强度进行了预测，并将结果与LightGBM、多层感知机（MLP）和支持向量机回归（SVR）的预测结果进行了对比。结果表明：与较单一的LightGBM、MLP和SVR算法相比，CRITIC-LightGBM模型预测的平均绝对误差和均方根误差更小，准确性更高，R2更接近1，模型的泛化能力明显提高。 Abstract: In order to predict the compressive strength of concrete more accurately, cement, slag, fly ash, water, water reducer, coarse aggregate, fine aggregate and age were used as the prediction indexes of concrete strength. The CRITIC algorithm was used to weight the indexes. On this basis, a new machine learning algorithm Light Gradient Boosting Machine(LightGBM) was introduced to calculate and train the samples. At the same time, the K-10 fold cross-validation method was used to optimize the model parameters. Finally, the CRITIC-LightGBM model for predicting the compressive strength of concrete was established. The model was used to predict the compressive strength of concrete, and the prediction results were compared with those of LightGBM, multi-layer perceptron(MLP) and support vector machine regression(SVR) algorithm. The results show that compared with the relatively single LightGBM, MLP, and SVR algorithms,the CRITIC-LightGBM prediction model has smaller mean absolute error and root mean square error, and has higher accuracy. R2 is closer to 1, and the generalization ability of the model is significantly improved.

戚喜章,吴雨航,钱大桐.基于CRITIC-LightGBM算法的混凝土强度预测模型[J].混凝土与水泥制品,2024(9):17-20,27. QI X Z,WU Y H,QIAN D T.Prediction model for compressive strength of concrete based on CRITIC-LightGBM algorithm[J].China Concrete and Cement Products ,2024(9):17-20,27.

摘   要：研究了水玻璃碱激发剂对不同粉煤灰（FA）掺量的淡化海砂海水混凝土（DSSC）坍落度、抗压强度、氯离子固化能力的影响，并进行了微观分析。结果表明：单掺FA可以增加DSSC的坍落度，而单掺水玻璃则会降低DSSC的坍落度；复掺时，当FA掺量为6%、水玻璃掺量为2%时，DSSC的抗压强度最佳；当FA和水玻璃掺量分别为30%和1%时，DSSC的氯离子固化能力最佳；DSSC中存在C-S-H凝胶对氯离子的物理吸附以及化学结合形成Friedel盐；当FA和水玻璃掺量分别为18%和1%时，DSSC的综合性能较好。 Abstract: The effect of water glass alkali activator on the slump, compressive strength, and chloride ion solidification property of concrete with desalinated seasand and seawater(DSSC) with different fly ash(FA) contents was studied, and microscopic analysis was conducted. The results indicate that the single addition of FA can increase the slump of DSSC, while the single addition of water glass can decrease the slump of DSSC. When mixed, the compressive strength of DSSC is optimal when the FA content is 6% and the water glass content is 2%. When the content of FA and water glass is 30% and 1% respectively, the chloride ion solidification property of DSSC is optimal. In DSSC, C-S-H gel can adsorb chloride ions physically and chemically to form Friedel salt. When the content of FA and water glass is 18% and 1% respectively, the comprehensive performance of DSSC is better.

杨健,徐敏,杜洪宇,等.碱激发粉煤灰对淡化海砂海水混凝土性能的影响[J].混凝土与水泥制品,2024(9):21-27. YANG J,XU M,DU H Y,et al.Effect of alkali activated fly ash on the performance of concrete with desalinated sea sand and seawater[J].China Concrete and Cement Products ,2024(9):21-27.

摘   要：研究了葡萄糖酸钠（SG）与聚羧酸减水剂母液（PC-A、PC-B）复掺对水泥基材料性能的影响，并分析了其协同作用。结果表明：当SG、PC-A单掺时，在相同掺量下，SG对水泥净浆流动度及胶砂减水率的提高有一定的效果，但其减水性和保坍性远低于PC-A；SG、PC-A、PC-B三者复掺时，在水泥颗粒上存在竞争吸附，SG可使聚羧酸减水剂更好地发挥其减水性和保坍性，具有较好的协同作用；从工作性来看，RK-A-7组的SG与聚羧酸减水剂母液复掺比例为最佳；从凝结时间来看，RK-A-4组最佳；从抗压强度来看，RK-A-6组最佳。 Abstract: The effect of sodium gluconate(SG) and polycarboxylate superplasticizer mother liquor(PC-A, PC-B) on the properties of cement-based materials was studied, and their synergistic effect was analyzed. The results show that when SG and PC-A are added separately, at the same content, SG has a certain effect on improving the fluidity of cement paste and the water reduction rate of mortar, but its water reduction and slump retention are much lower than PC-A. When SG, PC-A, and PC-B are mixed together, there is competitive adsorption on cement particles. SG can better enhance the water reducing and slump retaining properties of polycarboxylate superplasticizer, and has a good synergistic effect. From the perspective of workability, the optimal ratio of SG and polycarboxylate superplasticizer mother liquor is achieved in the RK-A-7 group. From the perspective of setting time, the RK-A-4 group is the best. From the perspective of compressive strength, the RK-A-6 group is the best.

CHANG J C,WANG Y H,HU H L,et al.Study on the synergistic effect of sodium gluconate and polycarboxylate superplasticizer in cement-based materials[J].China Concrete and Cement Products,2024(9):28-34,37.