Brittleness of High-Strength Lightweight Aggregate Concrete

Modern society and infrastructure are facing an increased demand for fast construction. A number of viaducts are aged and will need to be replaced in near future. When considering this replacement task, lightweight, slender bridge is the solution. Dead load reduction and high-strength to weight ratio are the main advantages when using the lightweight aggregate concrete (LWAC). Still, structural applications of LWAC are lacking. The main disadvantage of LWAC compared to regular concrete, which refrains its wider structural application, is its brittleness and uncontrolled crack propagation, especially when LWAC is exposed to compression. One of the ways to improve brittleness and increase the ductility of concrete is by addition of fibers. In this research, preliminary study is performed where fiber reinforced LWAC mixture was designed and tested. The mix consisted of lightweight aggregate Stalite, leading to high-strength LWAC and polyvinyl alcohol fibers (PVA) providing reduced brittleness and explosive failure. Results on fracture behavior and compressive strength with the increased amount of fibers were investigated and showed promising behavior. In future, structural tests (e.g. compression tests on prisms and beams) will be performed to further verify the benefits of combining aggregate Stalite with PVA fibers for structural applications of high-strength LWAC.