| 1. BackgroundAs traditional structure masonry have been applied for thousands of years. Today, masonry material is still used in our cities and countries. And all kinds of buildings built by this material are account for 70~90 percent. But this structures has manifest shortcoming, such as big dead weight, less anticrack performance, especial due to the clay brick's widely application and occupation fields, which affect the production of agriculture and industry and sustained development strategy. In order to solve the problem, clay brick is forbidden to employ in the cities.On the other hand, as a main nation of producing and using coal, the factories in our country emits large fly ash, which is the problem to be solved at short notice.Non-sintering and high-content fly ash brick can low weight > save the ground-, use the waste> reduce the environment and improve the architectural functions. To the full extent it can relieve the pressure caused by the accumulation of the fly ash and the prohibition of the clay brick. It's application has been listed to the development catalogue on the newly building materials and products.2. ApplicationOur nation have acquired great achievements of the fly ash application. Apart from being used in road material as the concrete additive instead of a part of cements, fly ash also is made panel wall and brick as the main material. Because the facture need condition of steam curing and compressing, the complicated technology, rigid operation and relatively high costs, so the application is limited.The special research on the facture and ratio of the high content fly ash brick has been carried out by Civil Engineering Institute of ZhehgZhou University. The specimens are made in the condition of compression and natural curing. According to the different grade, the optimum combination is obtained by adjusting the ratio of materials and content of additives. The result show that all kinds of index, such as, compressive strength, specific absorption and freezing thawing, can meet the requirement.3. The research objective and contentNow, the study about the fly-ash brick hasn't proceeded in our country. So the contents and results of this article can provide test data for adapting correlative rules and perfecting The Design Code of Masonry Structures (GB 50003 - 2001), and can promote amplitude application of fly-ash brick in practical engineering also.By the way of this aim, the paper carried out following works:1). According to the current Chinese code of The Standard Experiment Method of Masonry Basic Mechanical Property ( GBJ 129-90), the non-sintering and high-content fly-ash brick's basic material experiment is studied, and the strength is obtained.2). According to the study on experiments of 30 compressed specimens in which fly-ash brick is critical bearing material, the questions on the compressive strength of the masonry with different grade of the mortar is analyzed, the stress-strain relation is determined, recommended standard and designed value of the compressive strength is obtained.3). Studying on the experiments of 30 sheared specimens in which fly-ash brick is critical bearing material, the questions on the shear strength of the masonry with different grade of the mortar is analyzed, recommended standard and designed value of the shear strength is obtained.Experimentation study1. Design1). The compressive strength of the ten pieces of bricks selected at random is determined by the standard test methods.2). The two group specimens are made in the identical curing conditions in a unit that is made up of the same grade and ratio. The compressive strength is tested by the standard method.3). The 30 standard compressive specimens are produced according to the demand which are applied by the three grade mortar, i.e. M5^ M7.5 and M10. The axial and lateral deformations per grade of load are measured by percentage meters. The axial force is brought to bear by the jack and counterforce beam, the failure load value is m... |
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