Development of cement-based lightweight composites – Part 1: Mix design methodology and hardened properties

Abstract

a b s t r a c tThis article aims at the development of durable cement-based lightweight aggregate composites, with a good balance between the thermal and mechanical properties. The mixtures are developed with the optimized packing applying the modified Andreasen and Andersen model, to obtain the optimal target grading curve of all the solids in the mixture. A lightweight material produced from recycled glass is used as the lightweight aggregates (LWA) in order to obtain the desired low thermal conductivity.The properties of the designed composites, including the flowability and relative viscosity in fresh state, and the porosity, strength and thermal properties in hardened state are investigated. The porosity of the developed composites is studied by both modeling and experiments. Results indicate that there is a certain amount of closed internal LWA pores in the composites, which contributes positively to a better thermal insulation property. The developed composites have a low thermal conductivity while still retaining sufficient strength. Therefore, the designed composite can be used monolithically as both load-bearing element and thermal insulator.

Development of an eco-friendly Ultra-High Performance Concrete (UHPC) with efficient cement and mineral admixtures uses

“…As presented in the literature [44][45][46][47], different types of concrete can be designed using Eq. (1) by applying different values of the distribution modulus q, as it determines the proportion between the fine and coarse particles in the mixture.…”

Effects of Different Lightweight Functional Fillers for Use in Cementitious Composites

“…However such composites had lower mechanical strength and reduced overall performance. For example Yu et al used recycled expanded glass and achieved 28-day density of the composites as low as 1280 kg/m 3 with good durability, however, the corresponding compressive strength was limited to 23.3 MPa Yu et al 2013). Also, Chen and Liu developed expanded polystyrene foam composite with density of 400 and 800 kg/m 3 with excellent thermal insulation properties (lower thermal conductivity coefficient) but the extremely low corresponding strength values of 3 and 13 MPa hampered the use in structural applications (Chen and Liu 2013).…”

Mechanical Properties of Lightweight Concrete Produced with Expanded Glass Aggregate

“…Todėl, kuriant lengvojo betono mišinį, labai svarbu pasirinkti tinkamą lengvąjį gaunamos pagal specialią technologiją, aukštoje temperatūroje išpučiant stiklo duženas ir suformuojant porėtos struktūros užpildą. Šio užpildo naudojimą betonams, mechanines savybes ir ilgaamžiškumą tyrė Yu, Q. L. et al (2013), Spiesz et al (2013), Yu, R. et al (2016). Tyrimais nustatyta, kad naudojant šį užpildą galima gauti ypač lengvą, gerų termoizoliacinių ir stiprumo savybių betoną.…”

“…Tai reiškia, kad betonas su stiklo granulių užpildu labai greitai pasiekia savo projektinį stiprį. Tokį patį efektą savo tyrimuose pastebėjo ir Yu, Q. L. et al (2013). Stiprio sumažėjimą galima paaiškinti didesnėmis betono susitraukimo deformacijos iki apkrovimo (lyginant su įprastojo betono bandiniais).…”