Mechanics Performance Research And Numerical Simulation Of Pervious Concrete

As a kind of green environmental protection material,pervious concrete possesses the advantages of high permeability,less dosage of cement,and the construction is simple,while traditional concrete does not have these advantages. Pervious concrete in water permeability of concrete pavement,ecological slope protection and hydraulic structure have a wide range of applications. The permeable concrete pavement can alleviate the urban heat island effect,it has great significance to improve the city’s ecological environment. However,it is true that its high level of porosity results in lower strength, affects its popularization and application in engineering. Aiming at this problem,in this paper,by using the combined method of the experiment and numerical simulation,with the size of stone and dosage of fly ash as the main variables,the research of permeable concrete mechanics performance and permeable performance research was conducted,including the main contents:(1) Volume method was adopted to design the permeable concrete mixture ratio.The test data showed that permeable concrete compressive and flexural strength increased with the increase of aggregate diameter;block of the same aggregate diameter with the increase of porosity and compressive strength;in view of the permeable performance,large size of the permeable concrete permeable coefficient is much higher than the small particle size of permeable concrete;aggregate-cement ratio is an important factor to permeable concrete compressive strength.(2) Replacing part cement by fly ash was designed by using the quality method,preliminary adding amount was 0%,0%,10%,40%,elaboration adding amount was 16%,18%,20%,22%,24%.The results showed that:with the increase of dosage of fly ash,permeable concrete block porosity and permeable coefficient becomes smaller,but the magnitude of the drop is smaller the optimal dosage of fly ash is 20%. 28 d block strength decreases,60 d strength increased significantly,we can learn that fly ash was important to the later strength of pervious concrete.(3) Using Monte Carlo method,by means of applying APDL language of the finite element analysis software to write the pore on the program development,the generation method of the pervious concrete 3D model was put forward. The results show that the porosity distribution model of porous concrete more real to reflect the actual structure characteristics of pervious concrete.(4) The finite element software ABAQUS was adopted to simulate the permeable concrete the compression and bending simulation. The following conclusions could be obtained: with the increase of permeable concrete porosity,compressive strength decreased gradually;the bottom central area of trabecular model mainly bear the bending moment,high porosity leading to effective cross-sectional area decreases and lead to large local stress,then structure was destroyed;under the same displacement load,the internal stress concentration phenomenon near the hole wall area of high porosity model is relatively obvious,leading to premature material damage,thus forming a continuous fracture,the collapse of the hole and pore connectivity become the main causes of the damage of pervious concrete.