Study on Mortar Rebound Method for Masonry Structure Blocks of Concrete Products

The relevant provisions of the mortar rebound method in the national code GB/T50315 “Technical Standards for site testing of masonry engineering” is only focus on mortar rebound method of sinter bricks, but whether the rebound curve of sintered brick mortar can be used for non-sintered brick mortar is uncertain. Therefore, the rebound curve of non-sintered brick mortar needs to be further studied. The mortar rebound method of sintered bricks is used as a model for the research process for mortar rebound method of other blocks, and the mortar of three widely used blocks of concrete products in masonry structures is selected as the research object. In the end, the mortar rebound curves for mortars of three widely used blocks are obtained through relevant tests, the results showed that the mortar rebound curves of sintered brick and non-sintered brick are completely different, thus broadening the application area of the mortar rebound method.

Application of Shape Memory Alloys in Retrofitting of Masonry and Heritage Structures Based on Their Vulnerability Revealed in the Bam 2003 Earthquake

For decades, one of the most critical considerations of civil engineers has been the construction of structures that can sufficiently resist earthquakes. However, in many parts of the globe, ancient and contemporary buildings were constructed without regard for engineering; thus, there is a rising necessity to adapt existing structures to avoid accidents and preserve historical artefacts. There are various techniques for retrofitting a masonry structure, including foundation isolations, the use of Fibre-Reinforced Plastics (FRPs), shotcrete, etc. One innovative technique is the use of Shape Memory Alloys (SMAs), which improve structures by exhibiting high strength, good re-centring capabilities, self-repair, etc. One recent disastrous earthquake that happened in the city of Bam, Iran, (with a large proportion of masonry buildings) in 2003, with over 45,000 casualties, is analysed to discover the primary causes of the structural failure of buildings and its ancient citadel. It is followed by introducing the basic properties of SMAs and their applications in retrofitting masonry buildings. The outcomes of preceding implementations of SMAs in retrofitting of masonry buildings are then employed to present two comprehensive schemes as well as an implementation algorithm for strengthening masonry structures using SMA-based devices.