Study on Properties of Blue-Brick Masonry Materials for Historical Buildings

Abstract

There are a large number of historic buildings which were mainly made of blue-brick masonry in today’s world. However, for the natural and man-made reasons, these historic buildings have been damaged in different degrees. In order to protect historic buildings more scientifically and learn about the preservation state of existing historic buildings, it is necessary to ascertain the material properties of blue brick in historic buildings. The article takes the blue bricks of historical buildings in Kaifeng area of the Central Plains as an example to study. Through the analysis of physical properties, X-ray fluorescence spectroscopy, X-ray diffraction and scanning electron microscopy of blue brick specimens, the physical properties such as the apparent density, moisture content, porosity, and material structure composition are understood. The results show that the apparent density of blue brick is 1.64 g/cm3 , the moisture content is 10.23%, the 24 h atmospheric water absorption is 17.86%, and the porosity is 20.99%. The smaller the apparent density is, the larger the porosity is, and the water absorption performance is better. From the microscopic point of view, bonding ability between blue brick mineral particles is relatively weak. The pores between skeletons are large and the pore structure is obvious. From the perspective of material phase, the elements of blue brick are mainly O, Si, Al, Fe, and the composition of blue brick is mainly composed of quartz and feldspar. The softening coefficient of blue brick is 0.80, and the deformation and stability of the structure should be paid special attention in the rainy season or wet environment. Through the frost test, there are salt substances in the internal pores of the brick, and the surface of the blue brick is eroded and pulverized. In this paper, the experimental process and analysis methods for testing the material properties of blue brick can provide reference for the research on the material properties of the same kind of blue-brick masonry in historic buildings and masonry relics. The relevant material property parameters obtained in this paper can provide guidance for making protection schemes and scientific repairs for historic buildings in Central China, enrich the evaluation criteria for maintaining and reinforcing historic buildings, and provide theoretical support for studying the damage and health detection technology related to historic buildings.