Study On Vibrating Test Methods For Cement Stabilization Of Crushen Aggregate

Heavy compaction test method (HCM) and static pressure producing specimen method (SPSM) were put forward on the basis of 1990's compaction machine and construction level to adapt to traffic features at that time. Along with development of modern traffic (large traffic capacity, heavy axle load and other features) and upgrade of construction technique level in recent years, Heavy compaction test method and static pressure producing specimen method have gradually shown their inadaptability, which appears that test result cannot not only reflect actual performance of material, but also cannot effectively optimize material composition design and guide on-site construction, thereby affecting usability and service life of base course. Whereas this, it is of actual significance for this paper to carry out study and application for the vibrating test method on cement stabilization of crushed aggregate (CSCA).This paper firstly analyzes work characteristics of the vibrating roller, puts forward the vertical vibrating compaction testing machine of surface VVTM and fundamental vibrating parameters describing VVTM working performance by imitating the directional vibrating roller. On the basis of the most promising principle of VVTM working performance, through experimental study for influence orderliness on dynamic response and compacting effect of VVTM, this paper puts forward standard collocation of fundamental vibrating parameters (operating frequency 30Hz, nominal amplitude 1.2mm and debarkation system quality 180kg) and provides a standard for lectotype of the VVTM. On the basis of the principle of the vibrating compaction work equivalent to onsite rolling work, specimen is loaded into the specimen mould at one time by simulating actual construction process. Under the vibrating parameter standard collocation of VVTM, vibrating compaction is performed for 90s-120s. After vibrating compaction, the optimum water content scope is initially judged according to the mud-pumping situation of the specimen. The vibrating compaction test method (VCT) is put forward to determine the maximum dry density and optimum water content of CSCA. It solves existent defects on compaction mode, compaction work and water content ascertainment method and test operation process and other aspects, and is characterized by reliable result, good reproducibility and other features. The specimen is prepared according to the maximum dry density and optimum water content ascertained by the vibrating compaction test method. The sample of CSCA mixture is filled into the specimen mould at one time, then, the vibrating compaction is performed for 70s-80s under vibrating parameter standard collocation of VVTM. In this way, this paper put forward the vibrating producing specimen method (VPSM) to shape specimens. It solves some actual problems. For instance, the specimens shaped by SPSM cannot represent actual composition structure of CSCA, and physical mechanic property of test cannot truly reflect actual performance of CSCA because water content loses in specimens producing process by the SPSM, and coarse aggregate crush and compaction mechanism do not conform with actual vibrorolling forming mechanism. On the basis of the vibrating test method, gradual filling theory, multilevel dense built-in gradation is put forward. Reasonable cement dosage is put forward on the basis of the principle of equivalent ultimate strength; Mechanical behavior and endurance properties of CSCA are studied on the basis of the vibrating test method to reveal influence law of various factors on mechanical behavior and endurance properties of CSCA, and to provide theoretic basis for material optimization design and construction control. It establishes a splitting fatigue equation and tensile strength structural coefficient Ks=0.70Ne0.043 on the basis of the cylinder specimens of CSCA shaped by the vibrating producing specimen method, which are available for asphalt pavement design. It also puts forward anti-scouring performance of CSCA assessment index—scouring coefficient establishes relations between scouring coefficient Cs and roadway load action magnitude as well as action axis degree, which conforms to actual scouring mechanism on roadway and available for pre-estimating development scouring law of base course.Actual engineering applications indicate that CSCA designed by the vibrating method has excellent road performance, especially very strong crack resistance, which greatly appeases, even solves the shrinkage crack problem of CSCA and has evident economy, society and environment benefits.