Evaluation methods of workability of lightweight aggregate concrete

In order to make the construction convenience and ensure the quality, the fresh concrete should have fine workability. For the sake of the great difference of density between lightweight aggregate and cement mud, lightweight aggregate is easy to float at the surface of the fresh concrete, cause layer and segregation; and the function of water absorb of lightweight aggregate also cause great slump damage; at the pressure function, the lightweight aggregate will absorb the water which in concrete, this phenomenon usually make the lightweight aggregate to block up the pump, so the workability of lightweight aggregate concrete is more complicate than normal weight concrete. While evaluating the workability of lightweight aggregate concrete, we usually adopt slump value or slump value and slump flow to evaluation the workability of concrete commonly, but this method can't reflect the workability of lightweight aggregate concrete nicely. It is necessary to assist with the well-distributed coefficient of lightweight aggregate to evaluate the layer phenomenon of lightweight aggregate in refresh concrete, this method not only have the characteristic of simple and fast operation, but also can reflect the floating up of lightweight aggregate nicely.