Research On Road Rush-repair Self-compacting Concrete

Nowadays our country cement concrete pavement has accounted for more than 70% of the total have topdress.But as the traffic volume growth and vehicle weight increasing sharply, active service of cement concrete pavement damage is serious, need to be repaired.Applied to repair engineering materials in addition to should have hours strength and compatibility with the original road materials, should also have good maneuverability construction strength and long good durability.However, the existing repair material appeared more questions,such as:elastic modulus does not match with the original material, easy to aging,unstable defect.Therefore, this article on the basis of comprehensive analysis of the existing repair material characteristics, through the design and test, developed a kind of rush-repair self-compacting concrete material.And the self-compaction workability, mechanical properties, durability and cementitious system hydration products were analyzed and studied.First of all, using fixed water-binder ratio, design cementitious system, compound admixture, optimization methods of sand ratio, design a rush-repair self-compacting concrete. Among them, the fixed water-binder ratio of 0.31;Compound with compound admixture containing water reducing and coagulant gentle multicomponent, determine the water reducing group is divided into PC, coagulation components content of 0.04%, L retarded components identified as JS + NM, dosage of 0.05% + 0.05%;Determine the optimal sand at a rate of 48%.Second,research and study on the rush-repair self-compacting concrete optimizing groups, combined with the related test methods, analysis and study on its self-compacting workability, mechanical properties and durability.Self-compacting workability of material can be expressed as follows: slump extending degree of above 685 mm * 685 mm, U-shaped filling height above 335 mm, V funnel through time within 19.1 s;Compressive strength of the 2h is more than 20 MPa, flexural strength is greater than 3.5MPa, the late strength without shrinkage, strength in long age are stability;Material has better early shrinkage performance, wear resistance and carbonation resistance.Wear-resisting degree is greater than 2.20, 28 d carbonation depth is less than 4.1 mm.Finally, combining with microscopic test, such as X-ray diffraction(XRD), scanning electron microscopy(SEM) to explore the cementitious system of the rush-repair self-compacting concrete hydration process, identified the main hydration products.The research achievements of this paper are good for the development of cement concrete repair engineering materials.It has great significance and make an important role in promoting the application of road materials.