Concrete made with recycled tire rubber: Effect of alkaline activation and silica fume addition

Investigation on composite polymer and silica fume rubber aggregate pervious concrete

“…As per concluded by previous researchers, the strength of compacting concrete reduces because of the adding of rubber aggregate [3,[20][21][22] but both the flexural and compressive strength increase in case of adding rubber aggregate [1]. It is obvious from this research that by adding the silica fume to the modified rubber aggregate pervious concrete, both the flexural and compressive strength increase more that those without silica fume.…”

“…Waste rubber tire as fine aggregates can be an economical and sustainable alternative to river sand. Few studies have attempted to utilize waste rubber tire as partial replacement of fine aggregate in the form of rubber ash [1,3,5,[7][8][9][10].…”

“…Then to achieve higher strengths of the concrete, silica fume [3] was added, hence a new type of polymer-rubber aggregate pervious concrete is prepared. The mechanical properties of this concrete are investigated.…”

Optimisation of rubberised concrete with high rubber content: An experimental investigation

“…However, w/b was often varied with rubber content [38], which could Aiello and Leuzzi [17] Aliabdo et al [32] Batayneh et al [25] Bing and Ning(w/b=0.4) [33] Bing and Ning(w/b=0.6) [33] Correia et al [34] Flores-Medina et al [35] Ling [36] 3 possibly affect the hydration kinetics, mix porosity and ITZ density and width. Scanning Electron Microscopy (SEM) images have shown a lack of bonding (gap) between the rubber and cement paste at their ITZ, as well as limited hydration products surrounding the rubber particles [37][38][39]. Conversely, other studies show that rubber bonds well to the cement matrix [30,40].…”

“…To improve rubber-cement paste chemical/physical bonding [18], several rubber pre-treatments have been investigated such as washing with water [21,35,42], polyvinyl alcohol [43], NaOH [13,41,44,45], Ca(OH) 2 [46], silane coupling agents [47], organic sulphur compounds [48] or acid [40], as well as partial oxidation of the rubber surface [49], exposure to UV radiations [50] or pre-coating with cement [51], mortar [26], silica fume [39], limestone [52] or sand [45]. Despite some success in rubber pre-treatments (strength increase in the range of 3-40% [18,26,41,51,52]), results are often scattered and inconclusive, particularly when mixes with pre-treated rubber are not compared to mixes with as-received rubber [35,42].…”