Research On The Influencing Factors And Monitoring Of Construction Quality Of Cement-stabilized Cold In-place Recycling Base

The construction technology of cement-stabilized cold in-place recycling base has gradually been widely used in highway subgrade maintenance projects because of technical advantages such as convenient construction,lower cost,and waste utilization.However,due to the great difference of cold in-place recycling mixture,the relatively wide gradation range of secondary and below highway cement-stabilized cold in-place recycling base mixture in relevant technical specifications,and affected by the level of cold in-place recycling construction machinery,technology,the external environment(wind,sunshine intensity,etc.),it is difficult to comprehensively and accurately control the proportion of material consumption and gradation stability of cement-stabilized cold in-place recycling mixture,thus it is easy to cause problems such as segregation,insufficient strength and low durability of cold in-place recycling mixture.Therefore,it is of great importance to accurately grasp the factors influencing the construction quality of cement stabilized cold regeneration base to ensure the construction quality and improve the service life of the road.Firstly,the physical and mechanical properties of raw materials such as milling material,cement,and new aggregate were tested and the mix ratio of a recycled mixture was designed.The compressive strength,splitting strength,compressive rebound modulus,and dry-shrinkage performance of recycled mixture with three cement doses was studied respectively.In view of the three main factors affecting the performance of cold reclaimed mixtures in Inner Mongolia,an orthogonal experimental design was carried out by selecting cement dosage,cement gradation,and water content.7d unconfined compressive strength and 7d splitting strength were taken as test indexes to determine the influence of each factor on the strength performance of reclaimed mixtures at different levels.According to the construction characteristics of the cold recycling machine,the cement stable in-situ cold recycling base course test section is divided into a speed control section and a uniform speed section.The mixture gradation,cement dosage,and water content after on-site mixing are tested,and the two sections are calculated respectively.The coefficient of variation of each factor analyzes the cause of the variation of each factor and its influence on the performance of the recycled mixture.GPRS+GPS rolling monitoring system was used to monitor the rolling times and rolling speed of the cement stable in situ cold regeneration base in real-time.The sand filling method was used to measure the co MPaction degree of the test section.The influence law of the different vibrating rolling times and rolling speed on the co MPaction degree was studied,and the calculation method of rolling mass value was determined.The evaluation grades of rolling quality were put forward and the distribution positions and area ratios of different grades were determined.The construction quality control measures were put forward for the field test section of G207 Xilinhot section of Inner Mongolia cement-stabilized cold in-place recycling base.The study provides a reference for the design and construction quality control of the mixture for the cement-stabilized cold inplace recycling base in Inner Mongolia.