A simple mix design method for self-compacting concrete
ABSTRACT This paper proposes a new mix design method for self-compacting concrete (SCC). First, the amount of aggregates required is determined, and the paste of binders is then filled into the voids of aggregates to ensure that the concrete thus obtained has flowability, self-compacting ability and other desired SCC properties. The amount of aggregates, binders and mixing water, as well as type and dosage of superplasticizer (SP) to be used are the major factors influencing the properties of SCC. Slump flow, V-funnel, L-flow, U-box and compressive strength tests were carried out to examine the performance of SCC, and the results indicate that the proposed method could produce successfully SCC of high quality. Compared to the method developed by the Japanese Ready-Mixed Concrete Association (JRMCA), this method is simpler, easier for implementation and less time-consuming, requires a smaller amount of binders and saves cost.
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ABSTRACT: A particle-packing based mix design method, originally proposed by Brouwers, is modified and applied to the design of self-consolidating concrete (SCC) mix proportions. The essence of this method is to improve particle packing of the concrete system and reduce the paste quantity while maintaining concrete quality and performance. Using this method, a large matrix of SCC mixes, made of different aggregate types, sizes, and supplementary cementitious material (SCMs) types, was designed to have a particle distribution modulus (q) ranging from 0.23 to 0.29. Fresh properties (such as flowability, passing ability, segregation resistance, yield stress, viscosity, set time and formwork pressure) and hardened properties (such as compressive strength, surface resistance, shrinkage, and air structure) of these concrete mixes were experimentally evaluated. The concrete mixes designed using the modified Brouwers mix design algorithm and particle packing concept had a potential to reduce up to 20% binder content compared to existing SCC mix proportioning methods and still maintain good performance.Construction and Building Materials 11/2014; 70:439–452. DOI:10.1016/j.conbuildmat.2014.08.002 · 2.27 Impact Factor
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ABSTRACT: Self compacting concrete mixtures with the use of ladle furnace slag as filler and steel fibers as reinforcement were produced and tested in the laboratory. Different contents of ladle furnace slag filler, ranging from 60 to 120 kg/m3, and steel fibers, ranging from 0% to 0.7%, were used. The different mixtures were tested in the fresh state for fluidity, passing ability and resistance to segregation and in the hardened state for compressive strength, fracture toughness, freeze-thawing resistance and chloride penetration resistance. The test results showed that ladle furnace slag can be used as filler for self compacting concrete, as adequate consistency and workability was achieved, while compressive strength and durability were improved. Ladle furnace slag can also be combined with steel fibers, which considerably increase fracture toughness, in order to produce a high performance self compacting concrete using a low-cost industrial by-product such as ladle furnace slag.Materials and Design 07/2014; 59:454-460. DOI:10.1016/j.matdes.2014.03.030 · 3.17 Impact Factor
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ABSTRACT: The popularity of self-compacting concrete (SCC), as an innovative construction materials in concrete industry, has increased all over the world in recent decades. SCC offers a safer construction process and durable concrete structure due to its typical fresh concrete behavior which is achieved by SCC’s significantly different mixture composition. This modification of mix composition may have significant effect on the hardened mechanical properties of SCC as compared to normal vibrated concrete (NVC). Therefore, it is necessary to know whether the use of all rules and relations that have been formulated for NVC in current design codes based on years of experience are also valid for SCC. Furthermore, this study represents an extensive evaluation and comparison between mechanical properties of SCC using current international codes and prediction equations proposed by other researchers. Thus, in this experimental study, major mechanical properties of SCC are investigated for twelve SCC mixes with wide spectrum of different variables i.e. maximum coarse aggregate size, coarse aggregate volume and aging. In the present study, an extensive body of data reported by many researchers for SCC and NVC has been used to validate the obtained results.Materials and Design 07/2014; 59:199–210. DOI:10.1016/j.matdes.2014.02.054 · 3.17 Impact Factor