1. Use broken pebble the role of the physical properties of concrete
Pebble in the process of formation, the handling of water constantly in the process of extrusion, friction, lost the edges, surface is smooth, so it's less friction force on the ash concrete sand, we used the cobble crushing production of broken pebble of stone is obtained by sieving and grading is good, and less than artificial stone edges and corners, so use broken pebble mixing concrete has good workability. Relative than stone concrete, the broken pebble concrete of high content of coarse aggregate, sand ratio, both to ensure the concrete workability, easy to site construction, and reduces the production cost, improve the economic benefit. From the perspective of physical properties of the judgment, the broken pebble is suitable for concrete mixing.

2. Use broken pebble on the mechanical behavior of concrete
Use broken pebble mixing of C50 concrete mix with other two kinds of stone of C50 concrete, 28 d broken pebble concrete under same condition maintenance were 8.4% higher than that of pebble concrete compressive strength, and less than 2.4% of the crushed stone concrete, and three kinds of material preparation of 28 d compressive strength of concrete were greater than 50 mpa, meet the design requirements. Broken pebble concrete sand rate is 3% lower than the stone concrete, the former high coarse aggregate content, combined with the use of broken pebble grain composition is good, the needle flake content is small, mixing aggregate in concrete, distributed evenly, can effectively reduce the shrinkage of concrete cracks, the crack resistance of concrete is also can get effective control, durability has improved, has the high use value. Therefore said, from both from the physical properties and mechanical properties come up to the broken pebble concrete were analyzed, and it is suitable in the region under the condition of use.

3. The broken pebble concrete in the application of the simply supported girder bridge
Cameroon's sea river bridge upper structure by using precast post-tensioned prestressed concrete box girder, and precast concrete box girders after continuous construction, bridge etc are of C50 concrete cast-in-place layer. In box girder precast concrete, for example, using the broken pebble mixing C50 concrete has the certain superiority in the casting process. The order of the box girder concrete pouring is commonly: casting box girder floor first, and then pouring on both sides of the web, finally pouring roof and wing plate. Because box girder concrete construction process is relatively complex, construction for a long time, and higher requirements on the workability of concrete, concrete to keep slump, prevent slump through small pulp difficult lead to concrete, the lack of concrete cement mortar filling and not dense, concrete to have certain viscosity at the same time, can make the concrete in the process of unloading will not produce by flow segregation phenomenon, and be able to remain in the process of vibrating concrete uniform particles. We use broken pebble mixing concrete, proportion can improve the stone material, decrease the rate of sand, satisfy the construction of the concrete workability, but also can improve the quality of concrete, in addition, the use of high efficiency water reducing agent can reduce the water cement ratio, concrete mortar wrap cladding on the surface of the gravel, increase the viscosity of concrete, which can reduce the aggregate sinking caused by vibration.