| With the rapid development in infrastructure, long-span bridges together with, pile caps, anchorage blocks and towers made of mass concrete have found wide application. Nowadays, the thermal release speed of the cement is comparatively much faster than that in the past, this makes the thermal crack problem of the large mass concrete more outstanding and common.The heat of hydration releasing from the large mass concrete while it hardening leads to the temperature change and concrete contraction. This causes the corresponding stresses which are the main factors to form cracks in the mass concrete structures. Obviously, cracks will influence unfavourably the unity, waterproofing and durability of structure and become a hidden trouble. Thus, crack control must be considered while a large mass concrete structure is in construction.The thermal cracking problem of the large mass concrete is very complicated, which is related to structure;building material, construction, and even the circumstance. The current research on heat of hydration in large mass concrete is not enough and comprehensive. The covering area in the related codes is limited and narrow. Many issues appearing in construction have to be solved based on experience, rather than theory. This phenomena may lead to the waste of labour, material and financial resource.Based on the factor research which lead to the thermal cracking in large mass concrete and combined with the site test of temperature control of 8# pile cap in the TianChi Bridge across JinSha River, this thesis studies and analyzes the rules for changing of inner temperature field and temperature stress in large mass concrete, and discusses the actual effects of measures for heat of hydration control adopted in construction.The temperature monitoring and cracking control measurements for actual mass concrete in this thesis will not only provide useful information for similar engineering project, but also be used as a available reference for theory study andtest.
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