Study on compressive behavior and failure mechanism of a composite energy-saving wall made of recycled-concrete bricks

Abstract

Axial compression tests were conducted to analyze and compare the compressive behavior and failure mechanism of four wall specimens. The four wall specimens were: (1) a recycled-concrete brick wall; (2) a composite wall of recycled-concrete brick wall with a fly-ash block, (3) a composite wall of recycled-concrete bricks with an outside EPS insulation wall, (4) a composite wall of recycled-concrete bricks with an EPS insulation board. The compressive strength of all four specimens increased obviously with an increase in their thermal insulation. The bearing capacity and strain of the recycled-concrete brick wall with a fly-ash block showed an obvious increase compared with the recycled-concrete brick wall. In addition, its yield load and ductility significantly improved and the brittle failure mode clearly changed. Based on the experimental observation and failure-mechanism analysis of the composite thermal-insulation wall made of recycled-concrete bricks, a theoretical calculation model was established and the calculation formula for the compressive bearing capacity was suggested. Compared with the test results, the calculation formula for the bearing capacity was correct and reasonable. Therefore, it can be used in the design of composite energy-saving walls. Keywords: recycled-concrete brick masonry, axial compression, experimental study, theoretical analysis Avtorji so izvajali aksialne tla~ne preizkuse, da bi analizirali in primerjali obna{anje pod tla~no obremenitvijo in mehanizme po{kodb na {tirih vzorcih (stenah). Vzorci so bili pripravljeni iz: (1) recikliranih betonskih opek; (2) kompozitnih betonskih sten iz recikliranega betona, napolnjenih z bloki iz dimni{kega pepela; (3) kompozitnih sten iz recikliranih betonskih opek in zunanje EPS izolacije ter (4) kompozitnih sten iz recikliranih betonskih opek, napolnjenih s plo{~ami iz EPS izolacije. Tla~na trdnost vseh {tirih vzorcev sten je vidno nara{~ala z nara{~anjem njihove toplotne izolacije. Nosilnost in deformacija recikliranih betonskih opek, napolnjenih z dimni{kim pepelom, je vidno narasla v primerjavi z reciklirano betonsko steno. Plasti~nost in duktilnost sta se vidno izbolj{ali in krhka narava preloma se je spremenila. Na osnovi eksperimentalnih opazovanj in analize mehanizmov po{kodb kompozitnih termi~nih izolacijskih sten so avtorji izdelali teoreti~ni model za izra~un tla~ne trdnosti oz. nosilnosti preiskovanih materialov. Primerjava z rezultati eksperimentov je potrdila sprejemljivo ujemanje izra~unov nosilnosti na osnovi razvite ena~be. Tako se le-ta lahko uporabi za dizajn kompozitnih energijsko absorpcijskih sten. Klju~ne besede: zidanje z reciklirano betonsko opeko, aksialne tla~ne obremenitve, eksperimentalna {tudija, teoreti~na analiza