Research Of Key Technologies For Low Temperature Rising Mass Concrete

With the rapid development of design standards and construction technology,mass concrete in water conservancy and Hydropower Engineering, large bridges and high-rise and super high-rise building foundation engineering becoming increasingly important in today’s engineering field.The problem of mass concrete becoming increasingly severe with the size of large concrete structures becoming larger and larger nowadays. In order to reduce the possibility of thermal cracking,effective thermal control measures must be taken, which includes reduce the concrete’s maximum temperature rise and the temperature difference between inside and outside. A research of low temperature rinsing mass concrete technology is necessary.The technologies of reduce the temperature rise of mass concrete have been studied. Base on the research of predecessors, this article has the following research: Using ToniCAL7336 concrete hydration heat temperature instrument to study the effect on thermal properties of concrete by the water-binder ratio, mineral admixtures(fly ash and slag), the main admixture(superplasticizer, air entraining agents, retarders) and phase change ceramsite, the effects of the above factors on the other properties of concrete(compressive strength or durability) have been studied at the same time; An engineering example of mass concrete has been introduced and the thermal control results have been analyzed.The main innovations are as follows:1.Using ToniCAL7336 concrete hydration heat temperature instrument to study the effect on thermal properties of concrete by various factors, the situation that a large number of concrete must be mixed to research the thermal performance of mass concrete have been improved, the experiment have been simplified and the experimental accuracy have been improved.2.The effects of air-entraining agents for concrete thermal properties have been studied. Incorporation of air-entraining agents will reduce the temperature rise and the strength of concrete at the same time, the experimental results show that we incorporation of air-entraining agents while reducing the water-binder ratio can ensure the strength of concrete.3.The effects of seven commonly used retarder on the fluidity of cement mortar have been studied, the matching of retarder and superplasticizer also been discussed, the effects of retarder on concrete strength at different ages have been studied. All these can be the basis for the research and development of special admixture of mass concrete.4.The preparation of phase change ceramic in the condition below the atmospheric pressure have been studied, preparation of phase change ceramsite concrete by replacing the gravel with an equal volume phase change ceramsite, the effects of phase change ceramsite on the thermal properties and durability of concrete have been studied.