Applied Mechanics and Materials Vol. 711

Abstract: Cement mortar is an ideal similar material. In this paper,by using cement, sand and other materials to make the M5, M7.5, M10 three strength grades cement mortar, the effect of water cement ratio and cement dosage on the strength of cement mortar was studied. The changing rule of the cement mortar strength along with age was also analyzed.Through the test, the mortar mixture ratio that was consistent with the original rock mechanical properties was determined ultimately.

Abstract: In thermal power engineering construction, the main building is a great project, in which the construction time, key engineering technology is difficult. It is also a wide range, strong professional structure of the system, it is closely related to the development of construction technology, the need to gradually improve building materials production level and engineering practice. Main factory building structure system to achieve light weight, high strength, reliable technology, economy applicable, expanding for dry operation, should be combined closely with plant production process, good solution can be achieved. Therefore, choose the main factory building structure, give full play to the bearing capacity of each structure, improve the level of main factory building design, construction technology ,to accelerate the progress of main building structure system plays an important role.

Abstract: A linear polarization method was applied to measure corrosion rate of reinforced steel in concrete. The relationship between corrosion rate and mineral admixtures was discussed. The results show that changes of mineral admixtures material will affect the corrosion rate of reinforcing steel in concrete, of which slag is the most obvious.

Abstract: The destruction mechanism of carbon fiber cement was studied by Scanning Electron Microscopy with single fiber pull-out testing. The result showed that the interfacial strain increasing is accompanied with fiber pull-out, fiber fracture and interfacial debonding, which provides a basis for the analysis of numerical simulation.

Abstract: The first degree second order moment method (JC method) is applied to analyze the reliability of recycled aggregate concrete-filled steel tube (RACFST). Several performances are studies, which are the influences of different load combinations, specific values of loads,confinement coefficients and recycled coarse aggregate replacement percentage on the reliability of the column. It is found that the reliability index varied with the load combination and specific value of loads. The analytical results indicate that the reliability index of the round steel tube is higher than square steel tube and the influence of recycled coarse aggregate replacement percentage can almost be ignored It can be concluded that the formula had great influence on reliability index and the revised formula can meet the requirements of the ductility of structure reliability.

Abstract: In industrial buildings, reinforced concrete structure with low cost, superior corrosion resistance, fire resistance, while reducing regular, routine maintenance workload characteristics, widely used in thermal power plant room. But when the special process requirements and other conditions that restrict the construction site need to build span, height higher open plant, if the column structure is still using the traditional rectangular cross-section in the form of, in terms of force or from the economy are inappropriate. Double limb reinforced concrete columns flat belly bar, to solve this contradiction. This article will elaborate on the design and calculation methods flat belly bar double limb column.

Abstract: Three full-scale reinforced supported beams with different recycled coarse aggregate percentage were researched and compared in order to research their structural responses under different temperature. This paper investigated the impacts of recycled coarse aggregate on the strain of concrete, deformation and the bearing strength of specimen. The experiments show that the flat section assumption is available for RAC components. Besides, the failure force of RAC components is slightly poorer than that of NAC component. By analyzing a large number of studies, the predictions of bending failure strength and deformation of RAC specimen according to the code for design concrete structures (CDCS) are compared with the experimental results. Besides, the bending performances under room temperature and fire were compared.

Abstract: It is extremely complex for the seismic response of special-shape Concrete-filled-steel-tube arch bridge under severe earthquake, mainly in: the structure may enter elastic-plastic working state and nonlinear border, etc., with regards to this, the elastic-plastic beams unit of concrete-filled-steel-tube is introduced, using different boundary processing modes and establishing three different Midas finite element models. According to the second-level requirements of seismic probability level, regarding the artificial seismic waves as seismic input wave, it is carried out the three-dimensional seismic response of arch bridge. The results is showed that it have not yet entered elastic-plastic work scope for structure under E2 action of earthquake and the special-shape concrete-filled-steel-tube arch bridge is with the features of light deadweight and good seismic behavior.

Abstract: The ultrasonic method can be used for testing and analyzing the pore size of concrete. By studying the spectrum curves which is formed by ultrasonic transmitting at different thickness concrete panels can we get different time regular patterns of head waves formed by ultrasonic going through homogeneous concrete, compact grouting pore, grouting incompact pore, not grouting pore. All these provide a basis for predicting prestressed bellows pore grouting quality and judging whether there is interspace in pore. By artificially setting defects in bellows pore, for example, filling the pore to completely empty, 1/4 compact, 1/2 compact, 3/4 compact, fully compact and then embedding them in a concrete slab for ultrasonic testing. Test results show that the ultrasonic method can effectively evaluate the grouting quality of prestressed bellows pore.

Abstract: Lightweight aggregates glazed hollow bead, cement, foaming agent, foam stabilizer and waterproofing agents as the main raw material, produce foamed thermal insulation materials by vibration shaping. By adding emulsified stearic acid and methyl stearate alcohol organosilicon waterproofing agent, the effects of two types of waterproofing agent on quality of water absorption of foamed thermal insulation materials were studied, and the related mechanisms were discussed. Results show that the waterproofing effect of organosilicon waterproofing agents is superior to emulsified stearic acid, when the content of emulsified stearic acid and organosilicon waterproofing agent are 7% and 4% respectively, 2h,24h water absorption rate of samples are 18.34%, 45.45% and 14.45%, 32.83%.