Papers by Keyword: Cracking Temperature

Abstract: In the building construction project occupies an important position in the concrete , cracks appeared in the concrete work is more common , the cause of cracks in the concrete temperature control and crack prevention measures such as on-site concrete temperature were analyzed .

Abstract: The inorganic polymer concrete is a new environmentally material. Using the temperature - stress test machine to research its early cracking sensitivity, and compare it with the normal concrete. The deformation development process of inorganic polymer concrete consists three stages:early contraction, expansion, contraction to cracking; cracking temperature can effectively evaluate the overall cracking performance of concrete; the cracking temperature of inorganic polymer concrete is 14.2 °C, the normal concrete is 14.4 °C; the inorganic polymer concretes cracking stress is 2.658MPa, the normal concrete is 0.582MPa. The results show the inorganic polymers cracking performance is better than the normal concrete.

Abstract: Concrete cracking sensitivity made from different aggregates was compared with employment of advanced temperature and stress test machine by tracking thermal and stress development of concrete with age and elements distribution in interfacial transition zone of each concrete was explored by SEM and EDS. Test results indicated that compressive strength of concrete made from basalt and limestone was greater than diorite and natural aggregate and crack resistance of concrete based on cracking sensitivity comparison in terms of cracking temperature varying from minus 0.3°C to minus 2.5°C as diorite, basalt, limestone and natural aggregate. Elements Ca and Mg were apparently accumulated in vicinity of ITZ and some reaction between limestone and cement matrix might have taken place which blurred the boundary between aggregates and cement matrix.

Abstract: The advanced Temperature and Stress Test Machine was introduced to evaluate the cracking resistance of concrete with inclusion of light-burnt MgO under full restraint by tracking thermal and deformation development. Results showed that light-burnt MgO being incorporated ranging between 4 per cent and 6 per cent by mass of cementitious materials was beneficial to increase the maximum compressive stress and cracking stress of concrete by 0.37MPa and 0.2MPa on average respectively. The maximum temperature was slightly reduced from 59.8°C to 66.2°C while cracking temperature was significantly decreased from 0.8°C to minus 5.6°C. Sensitive anti-cracking coefficient F was forwarded to assess the early cracking tendency of concrete and in general, inclusion of 4 per cent light-burnt MgO with activity of 109s was rated the best in crack resistance.