The behaviour of brick masonry walls strengthened with four different patterns using welded wire mesh (WWM) overlay with mortar was investigated. The proposed WWM schemes are: (1) embedding WWM along the bed joint, (2) embedding WWM along the bed joint and a strip of WWM diagonally crossing on wall surface, (3) WWM alternately embedding along the bed joint and continuing to the surface of wall and (4) WWM fully covering on wall surface. Unstrengthened and WWMstrengthened specimens were subject to static out-of-plane flexural test with loading orientation perpendicular and parallel to the bed joint. The failure of the WWM-strengthened specimens with loading perpendicular to the bed joint was mainly due to rupture of the WWM while the failure of the WWM-strengthened specimens with loading parallel to the bed joint was mostly a sudden brittle failure. The flexural capacities of the walls specimens under perpendicular loading are higher in comparison with those of parallel loading. However, the flexural capacity is similar for both loading cases when the specimens are fully covered with WWM. The experimental results show that the adopted WWM-strengthening solutions produce a beneficial increase in flexural resistance, ductility and energy dissipation capacity making them suitable for strengthening of URM.
PurposeSelf-healing concrete is a revolutionary building material that will generally reduce the maintenance cost of concrete constructions. Self-healing of cracks in concrete structure would contribute to a longer service life of the concrete and would make the material more durable and more sustainable. The cementitious mortar with/without incorporating encapsulates at different percentages of slag replacement with the cement mix improves autogenous healing at different ages. Therefore, this study’s aim is to develop a self-healing cementitious matrix for repair and retrofitting of concrete structures.Design/methodology/approachIn the present work, waste straw pipes are used as a capsule, filled with the solution of sodium hydroxide (NaOH), sodium silicate (Na2SiO3) and colloidal nano-silica as self-healing activators. An artificial micro-crack on the control and blended mortar specimens at different percentages of slag replacement with cement (with/without encapsulation) is developed by applying a compressive load of 50% of its ultimate load-carrying capacity. The mechanical strength and ultrasonic pulse velocity, water absorption and chloride ion penetration test are conducted on the concrete specimen before and after the healing period. Finally, the self-healing activity of mortar mixes with/without encapsulation is analysed at different ages.FindingsThe encapsulated mortar mix with 10% of slag content has better self-healing potential than all other mixes considering mechanical strength and durability. The enhancement of the self-healing potential of such mortar mix is mainly due to hydration of anhydrous slag on the crack surface and transformation of amorphous slag to the crystalline phase in presence of encapsulated fluid.Research limitations/implicationsThe self-healing activities of the slag-based cementitious composite are studied for a healing period of 90 days only. The strength and durability performance of the cracked specimen may be increased after a long healing period.Practical implicationsThe outcome of the work will help repair the cracks in the concrete structure and enhances the service life.Originality/valueThis study identifies the addition encapsulates with a self-healing activator fluid that can recover its strength after minor damage.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.