Study On The Basic Characteristics Of Paper Clay Sculpture Material

This paper mainly studied the basic composition of paper clay sculpture building material. Moisture sorption isotherm models were fitted to the drying process. The variations of organic matter were taken the test in the retting system. The changing mechanism and microstructure characteristics were made a detailed discussion during hardening process. The application characteristics were conducted the system research. This paper was aimed at providing more quantifiable and inheritance of space for the improvement and development of the clay sculpture material.By studying on its drying process, results showed that: when clay sculpture materials were placed in the air under the constant temperature of 20℃, 30℃and 40℃, the time to achieve the dynamic balance was 7 days, 5 days and 4 days. At different temperatures, the Peleg model was the best isothermal absorption curve fitting model. The corresponding mathematical model were: 0.7535 10.7618.760 48.42 w wW = *A + *A(20 ℃), 0.7568 12.7028.393 78.92 w wW = *A + *A(30℃) and 0.8101 14.9238.505 106.8w wW = *A + *A(40℃). The environmental relative humidity had more influence than temperature on the drying process.By studying on its hardening process, results showed that: the initial setting time was 37.5 hours and the final was 85.0 hours. The shrinkage ratio was 12.8%. The corresponding mathematical expressions of phase content changes and relative crystallinity with the age were: Ca CO3(%):1Y =25.83*exp(-0.1939*t) +72.09*exp(-0.0109*t); Ca(OH) 2(%): 2Y =64.53 *exp(0.001711*t) -58.01*exp(-0.04071*t); relative crystallinity(%):3Y =23.53 *exp(0.0007343 *t) -7.610 *exp(-0.1262 *t). Harden process included drying, crystallization and carbonation. Carbonation was the main source of ultimate strength. At the early of hardening, it was non fixed crystal type. At the late, it tended to a steady state and had a fixed shape.By studying on its retting process, results showed that:changes of reducing sugar and amino acid were increased at the begining and then decreased. The end time of retting was about 30 days. The process of retting was interaction of lime slurry, microbial and enzymatic system. Glutinous rice flour enhanced crosslinked action and vicidity. It indeed produced alcohol in the retting, which may be produced by environmental microorganisms.By studying on its application characteristics, results showed that: drying samples had good freeze-thaw resistance, high humidity resistance and high temperature performance. The color of samples immersion in water became white after frozen, and surface ash layer burst and peeled off by high temperature rapid drying. Clay sculpture samples showed strong viscous liquid characteristics, and the characteristics of elastic solid were relatively weak. They were pseudoplastic fluid. Glutinous rice flour content had great influence on the dynamic viscosity in the low shear strength. It had certain hardness in the surface and certain toughness inside. Paper fibers could also enhance the strength of the surface layer and toughness of the internal. Glutinous rice flour could reinforce internal strength and surface oxidation hardness within a certain range. Quick lime had a beneficial effect on the surface and internal strength, but no special contribution to the toughness.