Evaluation of Performance of Matured Hydraulic Grouts: Strength Development, Microstructural Characteristics and Durability Issues

The present paper evaluates the performance of matured hydraulic grouts, with respect to their composition and the induced microstructural characteristics. Four different grout compositions were examined; three grouts based on natural hydraulic lime (NHL5), plain and in combination with pozzolan, and a ternary white cement - pozzolan - hydrated lime mixture. Both grout-only specimens and composite injected material have been examined and injected grout - masonry material interaction issues are discussed

Comparison of the performance of hydraulic lime- and clay-based grouts in the repair of rammed earth

Earth constructions constitute an important part of the built heritage and are spread worldwide. Rammed earth is among the most used earth construction techniques, though it exhibits a high seismic vulnerability. Nevertheless, the structural behaviour of rammed earth structures is still insufficiently comprehended. Thus, the preservation of this built heritage requires exhaustive characterisation of its mechanical and structural behaviours, as well as the development and validation of adequate intervention solutions. In this context, this paper presents an experimental program aimed at evaluating the effectiveness of grout injection to repair cracks and at further characterising the in-plane shear behaviour of rammed earth walls. The experimental program included the testing of rammed earth wallets under diagonal compression, which were subsequently repaired with injection of a clay-based or a hydraulic lime-based grout, and retested. Furthermore, sonic tests were conducted on the wallets before the destructive tests. The obtained results allowed to highlight that both grouts led to similar repairing performances, though the interlocking contribution promoted by the coarse particles of the rammed earth to the shear behaviour was found to be irrecoverable.Programa Operacional Temático Factores de Competitividade (POCI-01-0145-FEDER-007633

Seismic retrofitting solution of an adobe masonry wall

Adobe constructions represent a high percentage of the national patrimony, with high historical, cultural and architectonic value. Well preserved adobe structures can exhibit a particular architecture with very attractive geometric characteristics while also incorporating natural materials. However, the behavior of these structures is deficient under horizontal loads, such as those induced by an earthquake, which endangers their structural integrity and human lives. To develop a seismic retrofit solution, a real-scale wall was characterized and tested by considering permanent vertical actions with cyclic horizontal forces of increasing amplitude. To retrofit the wall, repair and seismic reinforcement solutions were developed and combined to evaluate their efficiencies. To repair the damages, hydraulic lime gum was injected by pressure into the cracks. The reinforcement solution included the use of a synthetic mesh in the wall. The retrofitted wall was then tested, and the results indicated that the retrofit solutions significantly improved the seismic performance of the wall. This study contributes to the characterization of walls constructed with adobe masonry and their behavior under horizontal actions. Furthermore, an economic, sustainable and efficient solution is presented for the retrofitting of adobe walls, with significant performance improvements obtained