Lightweight Aggregate Self-Compacting Concrete: State-of-the-Art & Pumice Application

Abstract

The scope of this study is twofold: first to present the current state-of-knowledge on lightweight aggregate selfcompacting concrete (LWASCC) and second to discuss the development of pumice aggregate self-compacting concrete (PASCC) falling in the LC20/22 strength class and D1.4 density class (as per EN 206-1). Former studies have showed that the commonly accepted range of values derived from fresh-state tests on normal weight self-compacting concrete (NWSCC) is also attainable for LWASCC, the majority of which is produced using artificial lightweight aggregates. The second part of the paper presents the findings of an experimental program that aimed to assess the effect of coarseto-fine pumice aggregates ratio on the rheological and mechanical properties of PASCC. Based on the results of this study it is verified that properly designed PASCC mixtures with a dry density in the order of 1400 kg/m 3 may be evaluated while in fresh state using the same test methods applicable for normal weight self-compacting concrete (NWSCC) and yield scores that lie within the commonly accepted ranges. If pumice aggregates are introduced in the mix in a saturated state, PASCC exhibits self-compactness similar to the one typically characterizing most NWSCC mixtures. Surface coating of fine and coarse pumice aggregates -though difficult in practice -improves workability and prolongs its retention.

Properties of self-compacting lightweight concrete containing recycled plastic particles

“…Workability is very important for SCLC [35]. Slump flow test and V-funnel test are usually performed to determine the fluidity of SCLC, and L-box test and J-ring test can be used to evaluate the ability of passing through steel bars [31][32][33][34][35][36][37][38][39][40]. Moreover, sieve segregation and settlement column tests are conducted to evaluate the segregation resistance of SCLC [36].…”

“…Moreover, self-compacting lightweight concrete (SCLC) has been gradually applied in practical engineering particularly in large-span bridge structures due to the light self-weight, ease of construction, lower on-site noise level, etc. Coarse aggregates used in SCLC often include expanded shale [31], expanded clay ceramsite [32], pumice [33], expanded polystyrene [34], etc. All the coarse aggregates are so light that they may float in the cement paste.…”

Cork waste in cement based materials

“…It is known that cork contributes to enhancement of these properties when included in construction materials. Other researchers have produced Lightweight Self Compacting Concrete (LSCC) using different types of lightweight aggregate and a combination of fine materials including cement and ground calcite filler [32,33], flyash [34,35], silicafume [33; 35, 36], glass powder [33] and also filler from recycled old concrete [35].…”

Effect of Thin Cementitious Crust on the Mechanical Properties of Lightweight Pumice Aggregate Concrete

“…Lightweight pumice aggregates have many pores on its surface, as shown in Figure-1. Thus, pumice aggregate coating with a thin cementitious crust appears to increase the workability of pumice aggregate self compacting concrete [9].…”