Factors effecting on the compressive and tensile strength of reactive powder concrete made with local materials

Abstract

Ultra High Performance Concrete (UHPC) represent as one of the most concrete progressive development so that it can be improved the strength, durability, reliability, and resilience of the concrete structures. The availability of local materials play the main role in the major step in making the economic mix jobs by saving their materials and effort and decrease the concrete cost. So in this paper, the parameters including the curing regimes, of sand gradation, binder type, and content, and steel fiber content were investigated to show their effect on concrete’s compressive strength. The obtained results showed that the curing regime that consists of 5 days (2 days at 60°, 3 days at 80°) given the highest strength than other curing regimes. Finer sand, Silica Fume, steel fibers cause a considerable increasing in compression strength. Various relationship were obtained illustrating the effect of studied parameters with concrete strength.

Effect of steel fibers on the performance of an economical ultra‐high strength concrete

“…66 or 6% by volume in the studies of Pourbaba et al, 65 Abbas et al, 8 and Nehdi et al 56 Nevertheless, any fiber dosage exceeding 5% by volume tended to have a negative impact on the economic aspect of concrete, so this value was selected as the upper limit in this cost evaluation. Table 5 and Figure 11 presented a cost estimation of several existing mix designs 8,17,51,66,[85][86][87] based on their components. The contribution of steel fiber to the total expense of concrete varied in a very wide range which was from 6% to 106% of non-fiber concrete costs.…”

“…Table 5 and Figure 11 presented a cost estimation of several existing mix designs 8,17,51,66,85–87 based on their components. The contribution of steel fiber to the total expense of concrete varied in a very wide range which was from 6% to 106% of non‐fiber concrete costs.…”

“…According to the database of Larsen and Thorstensen 35 collecting works involving micro steel fibers, a majority of investigations used straight fibers having a length (L) and diameter (D) greater than 13 mm and 0.2 mm, [36][37][38][39][40][41][42][43][44][45][46] respectively, while hooked-end fibers with length of 30 mm and diameter from 0.3 to 0.6 mm were most repeatedly examined. 40,42,44,[47][48][49][50][51][52] Only a minority of researchers considered smaller fibers such as L/D of 11/0.12 by Alomayri et al, 53 9/0.15 by Le Hoang and Fehling, 54 8/0.20 by Arel, 55 Nehdi et al, 56 and Abbas et al, 8 7/0.15 by Haque et al, 57 6/0.20 by Wu et al 58 and Balanji et al, 59 6/0.16 by Prem et al 60 and Gesoglu et al 61 or 6/0.15 by Erdogdu et al 62 The benefit of micro steel fibers has been well-documented in the literature. 35 Reducing the size of fibers could obviously provide a greater number of fibers than that of large fiber geometry in the same concrete batch.…”

“…In the literature, various contents of fiber in high strength concrete have been explored by many scholars. For example, Chkheiwer and Kadim 51 studied the mechanical behavior of fiber‐reinforced concrete at volume fractions V f of 0.5%, 1.0%, 1.5%, 2.0%, and 2.5% under various heat curing conditions. Abbas et al 8 and Pourbaba et al 65 experimented a mixture with fiber volume up to 6.0%.…”

Effect of Steel Fiber Type and Curing Regimen on the Mechanical Properties of Reactive Powder Concrete

“…They found the use of fly ash and nano-silica enhanced the compressive strength, and the percentage of silica foam ranges from 0.15% to 0.3%. Chkheiwer and Kadim [21] studied the effect of silica fume ratio, steel fiber percentage, curing, and sand gradation on the properties of RPC made with locally available materials. It was found that the optimum percentage of silica fume was 25% of the total weight of the binder.…”