关键词: 道路工程, 破碎卵石, 集料规格, 水泥稳定碎石, 半刚性基层

Abstract: The production, pavement performance and cement stabilized broken pebble(CBP) technical features of pebble produced in the main city of chongqing river were researched by factory investigation, laboratory experiments, field tests, mechanical analysis. The results show that the size of material plants is small, and products of single material plant are difficult to synthesize all required grading of pavement layers. Since the rough stone size was smell,mainmarn diameter of broken pebble was 26.5 mm. Because of gradation characteristics,CBP production should be at least 4 specification aggregates. Broken pebble crushed values was about 1/2 of local limestone gravel, and acicular flakiness content was less than 15% which was linear increase with crushed values, sand equivalent of pebble chips associated with 0.3 mm passrate was greater than 60%. Ash dosage, compaction degree were critical to CBP 7 day compressive strength (R7d), and the less gravel content generated the higher R7d.Structural differences between crushed gravel and cement mortar and the smooth interface was the main cause of worse R7d of CBP than cement stabilized limestone. In case of high ash dosage,structural bearing capacity quals to that cement stabilized limestone. Rubber tire rolling was critical to CBP compaction degree and optimum process was "(one weak vibration rolling+3 times rubber tire rolling)×2". Water content and delay in time affected compaction degree significantly. Poor curing CBP layer rolled by material trucks would result in damages due to shear, bending pull and edges thrust displacement. When lower layer modulus was higher, shear failure was main damage of poor curing CBP layer.Shear stress limit is about 0.5 MPa.

Key words: road engineering, broken pebble, aggregate specifications, cement stabilized macadam, semi-rigid base