Applicatoin Of Mixing MgO Shrinkage Compensating Concrete In Canal Lining

Large loss of canal seepage had always been a topic of concern in water conservancyconstruction, especially in today’s increasingly scarce water resources. One of the importantmeasures of the canal seepage project was that the crack seepage performance concrete beused. The main purpose of this paper was to study the characteristics of shrinkagecompensating concrete, determined to meet the compensation shrinkage concrete mixtureratio that requirements of channel lining, set a relatively accurate canal lining plate that crackseepage would be control, and proposed application methods. Researched and adoptreasonable canal seepage engineering technology, could reduce leakage losses effectively andeconomic efficiency would be improved.This article was divided into three parts to study. The shrinkage properties of concrete asthe research object in the first part. Combined with the structure and mechanicalcharacteristics of canal lining plate, trapezoidal channel lining board shrinkage calculationformula was deduced. The UEA-S expansive agent，MgO expansion agent water-cementratio were researched in the second part. Then, carry out the ternary quadratic rotationorthogonal experiment，got new shrinkage-compensating concrete mix and the optimal dosagecombination of limiting expansion. The third part, with the specific instances of canal liningplate, based on the theory of seamless, a set of suitable for the local climate conditions and theconstruction of canal lining board seepage control measures were developed. Mainconclusions gained can be expressed as follow:(1) According to the heat conduction equation and the third boundary condition,combined with the temperature variation, channel lining plate contraction mechanism atambient temperature effect was got. Similarly, according to the humidity diffusion equationwith boundary conditions, canal lining plate contraction mechanism under the influence ofambient humidity was got.(2) With UEA-S content, MgO content and water-cement ratio for the study, carrying outthe ternary quadratic rotation orthogonal experiment. Three factors sequence affecting theexpansion concrete limit inflation: UEA-S content＞water-cement ratio＞MgO content.UEA-S and MgO content restrictions on expansion of the influence of both showed increases first and then decreases. The limit inflation is better when content of UEA-S is10%, MgO is3%, and water-cement ratio is0.55.(3) Using the theory of seamless design, by the formula expansion joints spacing can beseen the consolidated temperature difference is reduced significantly after adding expansiveagent. Seamless design of canal lining plate need develop the specific construction programwhich base on the specific concrete shrinkage and expansive agent content.