摘  要：针对隧道二次衬砌混凝土对强度要求较低，对抗渗要求较高的情况，用低成本的含石粉机制砂，配制出了强度等级为C25，抗渗等级为P8的泵送混凝土。试验表明，机制砂中石粉含量为12%～14%时，配制出的混凝土强度较高；石粉含量为8%～16%时，能满足使用要求。Abstract:Aimingatthesituationthatthelowerstrengthbuthigherpermeabilityresistancerequirementsforthetunnelsecondaryliningconcrete,theC25pumpingconcretewithP8permeabilityresistanceispreparedwiththelowcoststonepowdermanufacturedsand.Theexperimentshowsthatwhenthecontentofstonepowderis12%～14%,thestrengthofconcreteishigher,andwhenthecontentofstonepowderis8%~16%,theconcretecansatisfytheapplicationdemand.

摘 要：针对目前粗钢筋连接技术发展迅猛的状况，总结、归纳了各类粗钢筋螺纹连接方法的特点、要点以及各自的适用范围。 Abstract: Aimed at the rapid development of the crude reinforced connection technology at present, the character, key point and their application scope of many kinds of the crude reinforced thread connection methods are summarized and concluded.

摘 要：分析了固定式钢棒切断机和连续式钢棒切断机的工作原理及对钢棒切断速度、切断精度的不同影响，并对提高切断机的切断质量提出了相关建议。 Abstract：The work principles of stationary steel bar cutting machine and continuous steel bar cutting machine and different influence of the two steel bar cutting machines on cutting speed, cutting precision of the steel bar are analyzed, and some suggestions about how to improve cutting quality of the cutting machine are put forward.

摘 要：高保水性砌筑水泥是一种新型的专用水泥，其制备砂浆的性能与预拌砂浆相近，但能耗和成本较预拌砂浆低。研究了高保水性砌筑水泥及其砂浆的保水率、抗压强度、拉伸粘结强度和收缩性等性能，参考我国砌筑水泥和砂浆的相关标准，提出高保水性砌筑水泥的性能指标，为高保水性砌筑水泥广东省地方标准的编制提供依据。 Abstract: The high water retention masonry cement is a new type of special cement, and the mortar made of it has the same performances as the ready-mixed mortar, while the energy consumption and cost of it can be reduced a lot. In this paper the water-retention, compressive strength, tensile bond strength and shrinkage ratios of high water retention masonry cement and mortar made of it are studied. And combined with the ready-mixed mortar standard and the masonry cement specifications, the performances indexes of high water retentive masonry cement are put forward as a reference for high water retention masonry cement standard of Guangdong Province.

摘 要：对混凝土梁式结构的健康状况进行检测鉴定，首先需要掌握其系统参数关于结构损伤的演化规律，以便进行有的放矢的检测和得到可靠的鉴定结果。本文以混凝土简支梁为例，通过静力加载试验模拟梁的损伤累积过程，通过突加荷载试验跟踪梁自振周期随加载损伤等级的变化，深入分析了这些变化的发生机理，并提出了一种基于自振周期的结构损伤程度识别指标。 Abstract: For the detection and evaluation of concrete beam structure, the evolution rule of its system parameters about structure damage should be grasped firstly. Then, the results of detection and evaluation may be reliable. In this paper, taking a simple supported concrete beam as an example, the accumulated damage of the beam is simulated by a static loading test, and the change of natural vibration period with loading damage is tracked by a shock loading test. The mechanism of the changes is analyzed, and an identification index of damage severity based on natural vibration period is presented.

摘 要：基于目前国内外的研究成果，以钢筋混凝土结构为研究对象，对钢筋混凝土材料的热工性能、力学性能以及高温粘结性能进行了研究分析；运用灰色系统理论对影响混凝土高温粘结性能的各因素进行了灰关联度分析。 Abstract: Based on the current domestic and international research results, taking the reinforced concrete beams as the study object, the reinforced concrete thermal properties, mechanical properties and high temperature bonding properties are researched and analyzed. The gray system theory is used for the impact factors of concrete high-temperature bonding performance, and the gray correlation analysis is carried out.