城市基础设施建设合理比例关系探析

城市基础设施是城市的重要组成部分 ,与城市经济发展和城市建设有着密不可分的关系。城市基础设施建设投资应与城市GDP、固定资产投资有适宜的比例 ,城市基础设施各专项之间也应有适宜的比例。通过实例的对比研究 ,希望能找出适合我国现状的比例关系。     

浅谈某大桥现浇箱梁大体积混凝土的施工

对混凝土配合比优选及原材料的选择进行了介绍,并对大体积混凝土温度应力进行了仿真计算,最后从浇筑温度的控制、冷却水管布置、混凝土养护及现场监控等方面阐述了其施工措施,以保证工程质量。     

威-团灌区多水源联合运用及优化配置

在灌区水源等基本资料的基础上,分析了多水源联合运用灌区的水资源优化配置问题。运用单纯型法,建立数学模型,借助Visual Basic编程进行求解,得到作物充分灌溉条件下的最大效益及相应的种植比例。     

基于玻璃纤维增强水泥（混凝土）材料性能分析的最佳配合比的研究

玻璃纤维增强水泥（混凝土）－－Glass Fiber Reinforecd C ement(Concrete），简称GRC，是国际上近30年来出现的新型建筑材料，有较高的抗拉强度，能增强阻裂性能，在对已开裂的墙体进行回固修复中能起到较好的作用。而在混合结构房屋中，砖砌 墙体的开裂很常见，为此，对GRC作基于材料性能分析的配合比研究，可为其应用于修复工作提供极为有价值的参考。     

南水北调中线渠道衬砌混凝土配合比设计

南水北调中线干线工程全长1 432km,渠道工程是该工程的主要组成部分.通过工程实例,介绍了衬砌混凝土配合比设计的全过程,提出了相应的施工质量控制措施.通过实际工程应用,论证了所配制的衬砌混凝土完全满足设计和规范要求.     

考虑应力作用下混凝土结构微观裂隙发展条件的腐蚀与耐久性探究

分析了混凝土结构耐久性劣化的内在条件与机理,阐述了应力作用下混凝土微观裂隙的形成与发展的条件,提出了改善混凝土结构渗透性,提高混凝土结构耐久性的技术措施,展望了混凝土结构耐久性研究的前景。     

The characterisation of foamed asphalt cement using a rotational viscometer

Warm mix asphalt using foaming technology is a widely used alternative to traditional Hot Mix Asphalt in the USA. However, there has been relatively limited research exploring the behaviour of the foamed asphalt cement, especially using traditional asphalt cement testing equipment. This research used the rotational viscometer to develop four new metrics that quantify the behaviour of foamed asphalt cement. These four metrics showed that increasing the foaming temperature increased the observed viscosity, but the initial observed viscosity decreased with lower asphalt binder grades. However, the point at which the observed viscosity crossed the actual viscosity increased with lower asphalt binder grades. Overall, the Wirtgen foamer had higher observed viscosity vs. the PTI foamer and provided a more robust foaming material. However, it is recommended that the AccuFoamer also be explored in future research, along with comparing laboratory produced foamed asphalt cement with field produced foamed asphalt cement.     

富浆胶凝砂砾石配合比设计试验研究

针对工程现场对于富浆胶凝砂砾石的适宜配合比设计经验不足的问题，基于双级配双重强度标准的“钻石带理论”和胶凝材料强度设计准则，采用常态拌和、加浆拌和两种生产工艺，通过正交抗压强度试验以及极差法分析，研究了胶凝材料用量、水胶比等参数变化对富浆胶凝砂砾石强度的影响，且得到了常态拌和工艺最细级配、平均级配的最优设计配合比以及加浆拌和工艺配合比。结果表明：在28,90 d相同设计龄期下，常态拌和胶凝砂砾石强度平均值约为加浆拌和胶凝砂砾石强度平均值的160～178倍。     

An investigation of the beneficial effects of adding carbon nanotubes to standard injection grout

Mortar grouting is often used in masonry constructions to mitigate structural decay and repair damage by filling cracks and voids, resulting in an improvement in mechanical properties. This paper presents an original experimental investigation on grout with added carbon nanotubes (CNTs). The samples were prepared with different percentages of CNTs, up to 1.2 wt% with respect to the binder, and underwent three‐point bending tests in crack mouth opening displacement mode and compressive tests. The results showed that very small additions (up to 0.12 wt% of CNTs) increased not only flexural and compressive strengths (+73% and 35%, respectively, in comparison with plain mortar) but also fracture energy (+80%). These results can be explained on the basis of a reduction in porosity, as evidenced by mercury intrusion porosimetry, as well as by a crack bridging mechanism and by the probable formation of nucleation sites for hydration products, as observed through scanning electron microscopy.