Mix Design Of Grouting Mortar And Investigation Of The Influence On Preplaced-Aggregate Concrete

As an alternative structural strengthening method, preplaced-aggregate concrete(PAC)strengthening method has its unique advantages in many situation ,such as water conservancy project, bridge strengthening ,especially suitable for reinforcement of columns .PAC can be the best solution for many repairs . Aggregate can be readily and tightly packed into confined areas needing repair-even those with limited access and with overhead obstructions. It's hard to use this method because of the strength of PAC is low which is caused of the Construction technology .thus, increasing the strength of PAC is the work of this paper.In this research, the author analyzed the structure, the failure mechanism and the strength influencing factors of PAC. The important factor is grouting mortar. In order to improve the performance of the grouting mortar, a series of additive contents of the admixture tests were carried out. Finally we get a series of grouting mortar with high strength,low shrinkage,high fluidity. It prepared for the latest experiment.The results reveal the relationship between the strength of PAC and the strength of grouting mortar. The PAC with the fly ash has a lower strength than the one without. The PAC with the slag has a higher strength than the one without. The test results showed that the axial compressive strength reached higher than 37.9MPa by using the mix-design. The strength of PAC meets the request of the code, so we can use the method in actual structures.The strength of PAC is liner with the strength of grouting mortar. The results show that the strength of PAC can increase 7.5Mpa because of the different combination of the grouting mortar. An important feature observed in the PAC was its failure by cracking through the stone aggregate particles. So we can get that the bond of grouting mortar and aggregate is an important factor to the strength of PAC.