Research On Performance And Engineering Application Of Colored Architectural Self-compacting Concrete

With the development of green building materials,traditional concrete can no longer meet the needs of the construction industry because of its poor durability and single tone,and there are often incidents of external wall tiles falling off in communities,schools and other buildings.Colored architectural self-compacting concrete concrete is made by mixing pigment into architectural self-compacting concrete and used as external wall structure,which can not only avoid safety problems,but also add a lot of color to the appearance of concrete.However,the addition of pigments will not only increase the cost of concrete,but also affect the performance of concrete.Therefore,exploring the influence of pigments on the performance of concrete and comparing and evaluating the engineering application effect of colored architectural self-compacting concrete and other decoration methods is not only of great significance,but also can lay a solid foundation for market promotion in the future.This paper intends to prepare concrete and mortar of three kinds of strength.Firstly,the suitable content of pigment is determined by preparing color mortar;secondly,based on the appropriate content,the experiments of slump extension,slump-flow time(T500)and cubic compressive strength are carried out to study the influence of the type and content of pigments on the performance of concrete under different strength grades,and improve the poor performance of concrete.Then,by simulating the light intensity and temperature in summer in Beijing,the light resistance of each color mortar under different intensity grades is studied.Finally,through an engineering case simulation,the differences of construction period and project cost of using colored architectural self-compacting concrete,paint and wall brick as exterior wall decoration are compared.The research results of this paper are as follows:(1)The data recorded by the chromatic aberration meter shows that with the increase of the pigment content,the four kinds of colored architectural self-compacting concrete all basically reach saturation at 5% of the pigment content,and no significant color change can be produced when the pigment is added.In contrast,the dyeing strength of red and yellow pigments is obvious,and 1% of the content can produce obvious color change,but the color change in the whole process of green and blue pigments is small,and there will be pigment floating phenomenon,so it is impossible to accurately know the actual content of pigment.(2)The tests of working and mechanical properties of concrete were carried out.The results show that the small amount of composite pigments(blue and green)has little effect on the working and mechanical properties of concrete,but a large amount of composite pigments(blue and green)may lead to the segregation of concrete and obviously reduce the mechanical properties of concrete.Inorganic pigments(red and yellow)have little effect on the mechanical properties of concrete,But increasing the amount of pigment(more than 4%)will obviously reduce the working performance of concrete.After changing the strength of concrete,it is found that with the increase of strength,the working properties of the four groups of concrete are improved to a certain extent,and the effect of composite pigments onthe mechanical properties of concrete is reduced.(3)When the raw material and mix ratio of concrete are improved,the working performance of colored architectural self-compacting concrete is obviously improved,and satisfactory working performance can still be obtained when the content of inorganic pigment reaches 8%(The slump extension and extension time of yellow concrete can reach 505 mm and 5.5s).Iron oxide red has no obvious effect on the early strength of concrete,but it will reduce the strength of concrete in the later stage.Iron oxide yellow can improve the hydration rate and efficiency of cement and improve the mechanical properties of concrete in the early stage,while the larger water absorption will obviously reduce the water-binder ratio of concrete and make up for the loss of later strength of concrete.(4)The light resistance of mortar was studied by ultraviolet aging test.It is found that inorganic pigments have better tolerance to ultraviolet rays,but composite pigments fade obviously with the increase of illumination duration(The value of color difference exceeds 3).Compared with two kinds of inorganic pigments,the yellow mortar specimens gradually turn red due to the poor heat resistance of iron oxide yellow.Higher strength specimens have better compactness,which can reduce the area exposed to sunlight to some extent and improve the light resistance of the specimens.(5)Through the simulation of engineering cases,the differences of the three decoration methods in the number of workers,construction period and cost are compared.The results show that the use of colored architectural self-compacting concrete can significantly reduce the amount of labor,shorten the construction period and reduce the project cost.