Research On Construction Technology And Application Of Slipfrom For Highway Collision-Proof Guardrail And Curb Stone

With the rapid development of China’s high-grade highways,the comprehensive implementation of green,environmental protection,mechanical fine construction is conducive to improving the quality of construction,speeding up construction progress and saving costs.The traditional prefabricated guardrail and curb stone construction is to build the prefabricated guardrail and curb stone on the base of the pavement.The construction progress is slow,the process is more,the site occupied is large,and the local interference and environmental pollution are great.Sliding form paving construction guardrail and roadside stone is one-time compact paving of fresh concrete guardrail or roadside stone at the base of pavement by using sliding form paver.Sliding form paving construction guardrails and curb stones have fast speed,small labor force,zero prefabricated sites,paved guardrails and curb stones have high overall structural strength,smooth and beautiful lines,which are comparable to works of art,and are favored by all walks of life.This technology has been widely used abroad and seldom used in China.The construction technology is that the cement concrete produced by mixing station is directly transported to the construction site by transport vehicles,and it can be called "3D printer of cement concrete".At present,the slip form construction technology is quite mature in terms of equipment,but the difficulty lies in mix proportion design,slump control and construction control.This paper studies the working principle of the slip form paver,the influencing factors of the surface quality of guardrails and curb stones,and the mix proportion design of slip form concrete,the selection of raw materials and the mix proportion of different cement concrete for curb stones and crash barriers.The influence of different influencing factors on its performance is studied.The technical difficulties of slump control and paving forming in sliding mode paving are successfully solved,and the application of paving in construction site is successfully carried out,the following findings have been draw:(1)by studying the construction technology and matters needing attention in the slip form paving of guardrails and curb stones,the concrete construction process is summarized as follows: laying out hanging lines mechanical positioning special guardrail: C15 concrete backfilling steel bar binding mixing and station discharging concrete transportation paving health maintenance cutting joints.Sliding form construction requires strict control of mixing time,admixture mixing,water consumption sensitive to slump,anti-pollution measures and so on.(2)through the analysis of economic benefits,it is concluded that the application of sliding-form paving construction technology can greatly reduce the construction cost and raw material cost,improve the construction efficiency,protect the environment and reduce pollution at the same time.(3)taking Renhua(Hunan-Guangdong border)to Boluo Highway Project in Guangdong Province as an example,it is illustrated that the popularization of the construction of Slipform Paving of roadside stones in Renxin Expressway LM1 has achieved fruitful results.The core of the construction technology of Slipform Paving of roadside stones lies in the mix proportion design of cement concrete,the control of cement concrete and workability,and the benefit lies in the completion speed of the base of the working face,with emphasis on the production and paving of the front and rear Construction control.The construction technology of highway anti-collision guardrail and edge stone sliding formwork machine is still a new technology in China.It is inevitable that the sliding formwork paving technology will replace the traditional construction technology of prefabricated installation in the future.