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Development of high thermal crack resisting mass concrete |
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| รหัสดีโอไอ | |
| Title | Development of high thermal crack resisting mass concrete |
| Creator | Kanin Pinitoppapun |
| Contributor | Krittiya Kaewmanee, Advisor |
| Publisher | Thammasat University |
| Publication Year | 2564 |
| Keyword | Fly ash, Limestone powder, Maximum size of coarse aggregate, Mass concrete, Adiabatic temperature rise, Thermal properties, Simulation model |
| Abstract | According to the large dimension of mass concrete, it will generally have a problem with the heat generation from cement hydration and the temperature difference between inside and near surface of the concrete that may lead to thermal cracking. Nowadays, many efforts are implemented to minimize thermal cracking potential in mass concrete structures. Existing materials and construction methods have limitations and cannot cope with the requirements, so new solutions with new binder and aggregate systems need to be explored. Supplementary cementitious materials or SCMs provided in concrete i.e., fly ash, limestone powder, etc., have been used widely to reduce the heat generation. SCMs have been reported to improve properties of concrete such as slump and slump loss, compressive strength, and temperature rise. To develop thermal crack resisting mass concrete, the investigation on the binder system and aggregate system should be done. In the case of binder system, the SCMs which are fly ash and limestone powder are used as cement replacing materials. To control the temperature difference in mass concrete, the reliable temperature prediction model is required. There are some existing temperature rise prediction models that have been developed to simulate the temperature rise for mass concrete. However, those proposed models were still not considered for ternary binder i.e., cement containing fly ash and limestone powder. In the case of the aggregate system, the temperature rise of concrete with the maximum size of coarse aggregate (Gmax) equal to 1 inch instead of ¾ inch is investigated. Moreover, the experiments on slump and slump loss, compressive strength, and tensile strain capacity were done for both binder and aggregate system investigations.The study reveals for the investigation on the binder system that higher cement content mixtures show higher compressive strength, tensile strain capacity (TSC), and semi-adiabatic temperature rise. The adiabatic temperature rise prediction model for ternary binder system was done by considering degree of hydration, degree of pozzolanic reaction, total heat generation, free water content, and thermal properties. The proposed adiabatic temperature rise prediction model was then verified and showed reasonable accuracy with laboratory results. For the investigation on the aggregate system, the experimental results show that the mechanical properties which are compressive strength and tensile strain capacity of concrete are improved with the concrete containing maximum size of coarse aggregate equal to 1 inch instead of ¾ inch. Moreover, the maximum temperature rise for concrete was also reduced when Gmax 1 inch was used in the concrete. |
