Zhang Zhong-Jian, Liu Jian-Bin, Li Biao, Yang Xi-Guang
Department of Civil Engineering, School of Engineering and Technology, China University of Geosciences, Beijing, no. 29 Xueyuan Road, Haidian District, Beijing 100083, People's Republic of China.
Department of Building, Civil & Environmental Engineering, Concordia University, 1455 de Maisonneuve Blvd, W., EV6.166 Montreal, Quebec, Canada H3G 1M8.
R Soc Open Sci. 2018 Oct 31;5(10):180779. doi: 10.1098/rsos.180779. eCollection 2018 Oct.
Thermally induced deterioration behaviour can cause severe weathering in marbles. Most previous studies focus on the deterioration behaviour of calcitic marbles. Relevant studies of dolomitic marbles are generally carried out under a 'high temperature and low cycling times' condition. Little attention is focused on the deterioration behaviour in dolomitic marbles when they are subjected to a large quantity of heating-cooling cycles under a 'low temperature and high cycling times' condition. This paper presents experimental investigations on the thermally induced deterioration behaviour of two Beijing dolomitic marbles (Qingbaishi Marble (QM) and Hanbaiyu Marble (HM)) under heating-cooling cycles up to 1000 cycling times. The applied temperature range is from -20°C to 60°C which is to simulate the seasonal temperature variations in Beijing city, China. Related properties such as weight loss, three-dimensional microtopography, elastic wave velocity and uniaxial compressive strength were measured at certain cycles. The results indicate that thermally induced deterioration behaviour will result in a continuous weight loss in dolomitic marble samples. Mechanical properties of those two marbles are strongly affected by heating and cooling treatments, which were reflected by the reductions of dynamic Young's modulus and uniaxial compressive strength with an increase of thermal cycles. Compared with QM, HM displays a higher level of thermally induced deterioration which should be due to the abundance of quartz mineral.
热致劣化行为会导致大理石出现严重风化。以往的大多数研究都集中在方解石大理石的劣化行为上。白云石大理石的相关研究通常是在“高温和低循环次数”条件下进行的。当白云石大理石在“低温和高循环次数”条件下经历大量加热-冷却循环时，其劣化行为很少受到关注。本文介绍了对两种北京白云石大理石（青石大理石（QM）和汉白玉大理石（HM））在高达1000次循环的加热-冷却循环下热致劣化行为的实验研究。所施加的温度范围为-20°C至60°C，以模拟中国北京市的季节温度变化。在特定循环次数下测量了相关性能，如重量损失、三维微观形貌、弹性波速度和单轴抗压强度。结果表明，热致劣化行为会导致白云石大理石样品持续失重。这两种大理石的力学性能受到加热和冷却处理的强烈影响，这表现为随着热循环次数的增加，动态杨氏模量和单轴抗压强度降低。与QM相比，HM表现出更高程度的热致劣化，这应该是由于石英矿物含量丰富所致。
