The Study On Development And Paving Process Technology Of Large Size Dry Concrete Precast Blocks

With the continuous development of contemporary concrete technology,in order to meet production needs and speed up the construction process,which saves costs and resources,dry and hard concrete has advantages in terms of its low hydration heat,fast hardening and early strength,and low cost.A wide range of concerns.However,the research on dry and hard concrete is not perfect.Due to the zero slump of dry and hard concrete,the mix ratio and design method of ordinary concrete cannot meet the properties of dry and hard concrete.Therefore,it is necessary to study the forming characteristics of each component in concrete.Influence and explore the appropriate conservation system.The temperature in Heilongjiang Province is low,and the geological slope is seriously damaged by freeze-thaw cycles.The small-scale prefabricated slope is liable to produce uneven settlement,which affects both the safety of the embankment and its aesthetic appearance.The large-size dry concrete precast blocks of this study have a large span and a large area of coverage,and have little effect on uneven settlement of local geological slopes;at the same time,large-size dry concrete blocks are due to their surface area and volume.It is relatively small,less affected by permeation and freeze-thaw cycles,and has better adaptability to slopes in cold regions.However,due to its large size and weight,it is necessary to develop related paving machines and improve the construction process.This article focuses on the key technical issues in the application of dry and hard concrete in embankment slope protection projects,conducts relevant research on the preparation technology of dry and hard concrete,develops mechanized paving equipment,and makes corresponding supporting construction techniques,which can effectively speed up the construction progress and reduce a lot of labor This will greatly ease employment pressure and solve the difficult problems in the construction of dike projects in cold regions in China.In order to guarantee the quality and quantity of the Sanjiang governance embankments to meet the standard tasks,provide technical support.The research results in this paper provide technical support and theoretical basis for further promoting the application of dry and hard concrete in hydraulic engineering in cold regions,and have certain theoretical and practical significance.In this paper,by referring to a large number of related literature and viewing the construction site,relevant experiments have been designed to study the influence of various components of the dry and hard concrete on the strength of the embryo body and the intensity of each age,the influence of different forming methods on the compactness,and different The effect of curing methods on the strength of each age group is optimized from the aspects of dry hard concrete components,molding methods,and maintenance methods.At the same time,the development of related machinery and equipment,the specific results are as follows:(1)The reasonable water-cement ratio is between 0.3 and 0.43;the sand rate is between 33 % and 38 %;the pebble content should not exceed 50 %;the best dosage of fly ash is about 20 %;The amount is between 0.5 % and 1 %.(2)Impact-type pressurization Compared with the current vibratory pressurization,the compaction time is shorter and the compactness is higher.(3)Steam curing is more suitable for rapid rhythm production than standard maintenance and outdoor maintenance.The reasonable maintenance system is 5 h for rest,the reasonable heating rate should not exceed 20 °C/h,and the constant temperature should be 60~70 °C.Between the time,constant temperature 3 ~ 5 h is appropriate.(4)The vacuum suction cup plus small crane is used in the paving process of large-size induction concrete precast blocks to optimize the relevant flow of prefabricated block pavement.