摘 要：分别以30%、40%、50%和60%的铁矿尾矿细砂取代天然砂，并复掺矿渣微粉和粉煤灰，配制了C20、C30和C40预拌混凝土，试验研究了混凝土和易性、强度和抗氯离子渗透性等性能。结果表明，以30%、40%和50%铁矿尾矿细砂取代天然砂的各强度等级混凝土和易性均能满足要求；在60%取代率时，混凝土和易性较差，但强度仍能满足要求；50%取代率时，混凝土抗氯离子渗透能力与基准混凝土相当。 Abstract: Using iron ore tailings sand (OTS) in the ratios of 30%, 40%, 50% and 60% to substitute natural sands, and adding tiny slag powder and fly ash, the ready-mixed concrete with strengths of C20, C30 and C40 are prepared. The properties such as workability, strength and chloride ion permeability resistance of concrete are studied. The results indicate that with the OTS substitution ratio of 30%, 40% and 50%, these OTS-based concrete can meet the workability requirement. With the substitution ratio at 60%, its workability is relatively poor while its strength still meets the requirement. With the substitution ratio at 50%, the OTS-based concrete has the similar chloride ion permeability resistance to the normal concrete.

摘 要：介绍了现浇钢筋混凝土系杆拱施工工艺，就施工过程中容易出现的问题提出了需要注意的问题及解决方法。 Abstract: The construction process of ?cast-in-place reinforced concrete?tied arch is introduced, and the attention problems and solved methods is carried out during the construction process.

摘　要：介绍了氯氧镁水泥模壳免拆施工技术在天津宝境栖园地下车库工程中的应用情况，重点论述了模壳在车库现浇密肋楼板施工中的施工工艺、质量控制措施，并总结了施工体会。 Abstract: The application of non-dismantling construction technique of magnesium oxychloride cement formwork in Tianjin Baojing garden underground garage project is introduced. The construction technique and quality control measures of the formwork in the construction of cast-in-place concentrated beams plates in the garage are primarily discussed, and the construction experience is also summarized.

摘 要：介绍了PCCPL卧式缠丝机螺距控制装置改造前的工作原理、不足之处以及改造优化后的工作原理和优势。通过改造，降低了复杂设备系数，进而使设备的整体造价和维修费用明显减少。 Abstract: The working principle and disadvantages of a pitch control unit of horizontal wrapping machines of PCCPL before unit revamping, and the working principle and advantages after the pitch control unit revamping are introduced. Through the unit revamping, the complicated unit coefficient is reduced, and the whole cost for the machine and the maintenance cost are both greatly decreased.

摘 要：通过汶川和玉树两次地震的震害统计，分析了造成巨大人员伤亡和财产损失的原因，对我国广大农村房屋的抗震设防提出了采用基础滑移隔震技术的建议。基础摩擦滑移隔震技术较为成熟、造价低廉、简单易行，较适用于量大面广的村镇房屋建设。最后，对基础滑移隔震技术进行了探讨与应用前景的展望。 Abstract: Based on the seismic damage statistics in Wenchuan and Yushu earthquake, the reasons of caused so enormous personnel casualties and property losses are analyzed, and some suggestions of seismic fortification in the rural houses are proposed. Sliding base-isolation technique is mature, cheap and easy to do, more suitable for enormous quantity of housing construction villages. Finally, the friction sliding base-isolation technique is discussed and the development in the future is prospected.

摘 要：某框架剪力墙结构工程初期施工中，出现了楼板对角裂缝和跨中裂缝。经从结构、构造和施工多方面分析，主要是因板的抗裂能力不足引起的。后续施工中，采取在楼板上部加配双向抗裂构造钢筋网片、调整混凝土组分材料和配合比、改善混凝土性能的综合措施，成功解决了问题。 Abstract: Some floor diagonal cracks and mid-span cracks appeared in initial construction period of a frame-shear wall structure. By comprehensively analyzing from structure to construction, the crack is caused by the deficiency of crack resistance capacity of the floor. Then, the following measures are taken: such as configuration of bidirectional crack resistance reinforced, adjustment of components materials and mix proportion of the concrete, improvement of the concrete characteristics. The crack problem is resolved successfully.