| In recent years, historic buildings and town houses with masonry structure have suffered frequent floods and damaged severely. It causes not only losses of social and historical value but also life safety threat and economic loss. Current research on the mechanical properties of brick masonry under flood soaking concentrated in contrast to compression and shearing properties with short-term immersion within 24 hours. But the soaking time of actual flood may reach several days. So it is one of the undertaken urgently research that putting forward a method for soaked buildings to do reliability identification, strengthening and repairing reinforcement after floods through the mechanical property study of brick masonry under long-term immersion.It is focused on the compressive strength experiment of mortar, brick and masonry under different soaking time in this paper. Based on the classification of masonry, mixed mortar and lime mortar with different ratios are adopted. On the basis of experimental study, this paper, however, aims to explore the variation of compressive strength with immersion time and observe the failure phenomena of mortar, brick and masonry. The test shows that the trend of mixed mortar’s strength falls first, then picks up and falls again at last in wet and air-dry state. The strength of lime mortar in wet state is zero. There is a little variation for the strength in air-dry state but it will gradually recovery with the increase of the air-dry time. The strength of soaked brick decreases little under different immersion time, and the compressive strength of masonry gradually decreased with immersion time.It aims to analyze the mechanical properties of soaked brick masonry based on the results of experimental studies and existed literatures. Firstly, it is expected to establish a practical formula for soaked mortar strength by using a linear formula to fit the overall trend of mortar strength. There is a parameter modification work about compressive strength formula of soaked masonry based on the test value of soaked mortar, brick and masonry, and on the basis of it, a compressive strength formula of soaked brick masonry for practical is established successfully. Also, a model of soaked brick masonry shear strength formula is explored by summarizing results of existed literatures.Finally, based on the study of mechanical properties of soaked brick masonry, it is analyzed that what influence of masonry buildings’reliability caused by water immersion. Then reliability analysis of immersion impacted masonry buildings by flood is put forward based on the reliability identification of general masonry buildings. Meanwhile, for the historic buildings, a new repair method which combines the new material, namely XYPEX, and grouted pointing method is proposed for constructional strengthening and repairing. Also there is a test to identify the effect of bearing capacity and integrity of brick masonry grouted pointed by XYPEX. |
