大掺量“补钙”粉煤灰对泵送混凝土坍落度经时损失的研究

为加大粉煤灰在混凝土中的应用量,并保证混凝土经时损失不受影响的情况下,通过实验配制了不同粉煤灰掺量、不同"补钙"量的泵送混凝土,对照相应实验室配合比设计的水泥混凝土,来研究不同掺量"补钙"粉煤灰对泵送混凝土坍落度值及坍落度经时损失的影响。结果表明:不同掺量"补钙"粉煤灰对泵送混凝土的坍落度值及经时损失均有显著影响;当粉煤灰掺量在50%~60%、"补钙"量在5%~6%、并掺入2%的高效减水剂时,可明显提高混凝土的坍落度值,降低泵送混凝土的坍落度经时损失。该实验研究成果可显著降低商品泵送混凝土的成本并提高混凝土的可泵性,为大体积泵送混凝土工程的施工和质量提供一定的保障。

Slump Time Losses of Concrete With a Large Amount of Fly Ash and a Certain Content of CaO

In order to increase the fly ash amount in concrete and ensure the concrete slump time losses ,the project con-crete mixture is made up of different dosage of fly ash and CaO .It was contrasted to the cement concrete which is de-signed by laboratory proportioning .This paper analyzed the slump time losses of concrete with a large amount of fly ash and a certain content of CaO .Experimental results show that it has a significant impact on the slump time losses of con-crete when the pumped concrete was designed with different dosage of fly ash .It could obviously improve the concrete slump value and reduce slump loss when the dosage of fly ash was added by 50% ~60% ,CaO was added by 5% ~6% ,and 2% of high quality water reducer .The project research results will significantly reduce the cost of commodity pumped concrete and improve the pumpability of concrete .It is also good for the concrete quality and the construction of the large volume pumping concrete engineering .