Confect Of The High Early Compressive Strength, Slight Expansion, Self-compacting, High Compressive Strength Concrete And Study Of Its Performance

Concrete is the largest architectural materials in the world nowadays. It is very impotant to the development of natinal economy. It is necessary to improve the life-span of the useage of the concrete, and to reduce the economic burdens caused by the mending or reconstruction of the concrete. The concrete confected in the labortory always takes on perferable durability. However, some quality problems such as honeycombed concrete, spot surface etc. Apear in the practical course of construction just because of the workers' operational matters(over vibration or deficient vibration etc). And also because of some structural matters,some problems emerge.For example, the concrete where the reinforcing steel bars are very dense or the room is very narrow cannot be viberated easily. The hardened concrete can always apear quality problem if the fresh concrete workability is bad. And it will reduce the durability of hardened concrete.All the problems which are caused by workers' matter, the denseness of steel or the narrow room can be settled by using self-compacting concrete. But the total quality of cement and the others pozzolana material in self-compacting concrete is very high, even more the coarse aggregates are less than commonness, the volume stability of self-compacting concrete is not so good.In the paper, the high early compressive strength, slight expansion, self-compacting and high compressive concrete was made successfully by using normal technolgy and raw materials in Wuhan. The result of the experiment is aplicable. We try to confect self-compacting concrete by orthogonal design tseting, and try to control the slump of the self-compacting concrete not less than 250 millimeter and the slump flow of the concrete between 500 millimeter and 700 millimeter. Looking the water/cement+ pozzolana material ratio, the cement quantity per volume and percentage of slag as the factor level, Taking the concrete compressive strength of 1 day age and 3 days age and the dosage of superplasticizer as the control target, to select the best factor level, And then contine confecting self-compacting concrete.If a certain dosages of second-grade flying-ash(FA) and UEA are mixed into the concrete when we confect self-compacting concrete, the compressive strength of 1 day must be not less than 5 MPa, and the compressive strength of 3 day must be not less than 20 MPa. And if some flying-ash is mixed into the self-compacting concrete, the heat of hydration can be reduced. And also if some UEA is mixed into the concrete, it will produce a little expansibility and compensate the early shrinkage of the concrete so as not apear crack. To select two groups of mix proportions from the nine ones and then carry out the others tests, flexural strength, penetration resistance test, expansibility test and modulus of elasticity test. We can confect the high early compressive strength, slight expansion, self-compacting, high compressive strength concrete successfully whose properties are excellent.