住宅楼工程混凝土楼板裂缝分析     

薛国正 《河南科技学院学报》2006,34(2):71-72

通过对某商品住宅楼的楼板裂缝进行分析和处理，提出今后设计和施工中值得注意的若干问题及其预防技术措施。  相似文献   

Consolidation behavior of cement- and lime/cement-mixed column foundations   总被引：1，自引：1，他引：1  

蔡袁强  徐长节 《浙江大学学报(A卷英文版)》2002,3(5):507-512

The consolidation behavior of mixed in place cement- and lime/cement-mixed column was studied. Consolidation of the composite foundation was modeled as a three-dimensional axi-symmetric problem. The authors used the finite difference method to obtain the pore pressure variation with time at any location below the surface. A computer program developed by the authors was used to draw some interesting conclusions about the consolidation behaviors of cement- and lime/cement-mixed pile foundation. Finally, a combined model including the permeability coefficients of cement-mixed piles and soil, was studied and its feasibility was evaluated. Project supported by National Natural Science Foundation of China (No. 59908012) and Education Ministry of China  相似文献   

水泥粉喷桩在公路工程软基处理的应用     

乔乃洪 《连云港职业技术学院学报》2005,18(3):31-32,38

粉喷桩加固软土地基是基于水泥加固土的物理化学反应，形成复合地基，是桩和土共同承担上部结构传来的荷载，达到提高其复合地基承载力的目的；根据公路工程对地基条件的要求，结合地区软基特点，从设计、施工、质量控制方面介绍了连云港地区公路工程采用水泥粉喷桩加固软土地基的方法。  相似文献   

预制板楼面沿板缝产生裂缝的原因及防治措施     

石建成  唐平志 《怀化学院学报》2006,25(5):101-103

通过大量的工程调查,研究和分析预制板楼面沿板缝产生裂缝的原因,制定了板缝处裂缝的防治措施及产生裂缝后的处置方法·  相似文献   

城市道路旧水泥混凝土路面加铺沥青混凝土   总被引：2，自引：0，他引：2  

黄晓东 《泰州职业技术学院学报》2004,4(3):26-29

近年来，已使用一定年限的旧水泥混凝土路面急需维修、加铺改造工程日益增多，结合南京市老城改造中旧水泥混凝土路面加铺改造工程实践。通过对旧水泥混凝土路面加铺分析，结合路面加铺改造方案的设计及玻璃纤维格栅的应用、改性沥青的应用等，阐述了延缓和防止路面加铺产生的裂缝对提高城市旧水泥混凝土路面使用寿命的作用。  相似文献   

AG2助磨剂的助磨作用及对水泥性能的影响     

林玉梅 《荆门职业技术学院学报》2006,21(6):8-11

在对几种单组分试剂的助磨作用试验的基础上,着重研究了双组分AG2复合助磨剂对水泥粉磨助磨效果及主要性能的影响.试验结果表明:AG2系列助磨剂的助磨效果较好,使水泥的粉磨细度提高了38.45%,其中AG28使3 d2、8 d抗压强度分别提高20.72%、13.73%,特别是用量为0.01%的AG210,使细度提高62.78%,使28 d抗压强度提高12.06%,具有明显的增产节能降耗、提高产品质量的作用.  相似文献   

Preparation and characterization of metakaolin-phosphate cement     

ZHOU Xin-tao  SU Da-gen  ZHONG Ming-feng 《重庆大学学报(英文版)》2008,7(1):28-34

We prepared cold-setting cement with metakaolin from kaolin dehydrated at 800 ℃ and phosphate, and studied the phase composition, microstructure and setting reaction mechanism of the cementing material by means of infrared spectroscopy, thermogravimetry, X-ray diffraction, and scanning electron microscopy. The metakaolin-phosphate cement is predominantly amorphous, where the phases responsible for chemical setting are mainly amorphous aluminophosphate hydrates. The reactivity of metakaolin depends on the particle size. Metakaolin particles of 1.75 μm in D50 have an acid dissolution index up to 18.45%, and the reaction with phosphate at room temperature to form metakaolin-phosphate cement takes only 6 h. The so obtained cement shows a compressive strength of 92.5 MPa after 7 d and keeps its amorphous phase at 1 000 ℃, demonstrating better bonding and mechanical properties and higher stability at a medium or high temperature.  相似文献   

Pore structure of historic and repair Roman cement mortars to establish their compatibility     

Anna Klisi&#x;ska-Kopacz  Renata Ti&#x;lova  Grzegorz Adamski  Roman Koz&#x;owski 《Journal of Cultural Heritage》2010,11(4):950-410

Mercury porosimetry was applied to the study of pore structure of the historic Roman cement mortars representative of different locations in Europe and time periods as well as different application techniques from architectural castings to in situ formed renders and profiles. Three categories of pores were found to coexist in the mortars. The finest pores, with diameters below 0.1 μm, are present within the hardened aged Roman cement matrix. The larger ‘air’ pores, with diameters between 0.2–2 μm, are due to the evaporation of the excess unbound water and restricted hydration. Pores larger than 2 μm are rare and, in general, can be related to microcracking induced by shrinkage drying and mortar weathering. The mortars have rarely been found to develop a dense fine-porous microstructure characteristic of the ideal conditions of moist-curing; massive architectural castings being the only exception identified. The presence of larger ‘air’ pores was, in turn, almost universally observed. The investigations of the freshly prepared Roman cement mortars have revealed that the restricted hydration could be due to the exposure of the freshly laid surface to dry real-world external environments, a high water-to-cement ratio in the original mortars, or the drawing of water from the stucco mass due to insufficient pre-wetting of the porous masonry. The insufficient reactivity of historic cements, resulting from a high content of over-burned, non-reactive cement components or coarseness of the cement grains, could be another reason for yielding poorly hydrated mortars in the past. In general, Roman cement stuccoes are in an excellent state of preservation in spite of their usual exposure to polluted urban environments for more than a century. Therefore, the coexistence of Roman cement mortars of widely different pore structures has not brought about any problems of incompatibility which field observations could reveal. The Roman cement repair materials have been found to develop pore structures similar to those of historic mortars. Therefore, they are in broad terms compatible with historic masonry or stuccoes. However, the porosity and strength of the repair materials can be controlled by a careful manipulation of the water-to-cement ratio of the mix to adapt them better to the properties of the host material.  相似文献   

路面基层施工质量控制     

吴军 《淮北职业技术学院学报》2007,6(3):90-91

本文从原材料选择、混合料组成设计、生产及施工工艺、养护等各方面阐述了高等级路面基层用水泥稳定碎石的施工质量控制,重点论述了混合料组成设计及施工工艺的控制。  相似文献   

门座起重机变幅平衡梁管理研究     

吴启超  沈家桢  宓为建 《上海海事大学学报》1998,(4)

通过对门座起重机平衡梁的测试和检查,发现铰处腋部有裂纹,经静强度和疲劳强度的计算复校,并与门机测试结果相对照,得到了平衡梁腋部裂纹系疲劳所致的结论。该结论对我国近千台港口门机管理有积极意义。本文对已经开裂的平衡梁所应采用的管理方法进行了探讨。  相似文献