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.
- SourceAvailable from: Nader K. A. Attari
[Show abstract] [Hide abstract]
- "This research was included twelve beam column connections with different percentage of reinforcement. Many other researchers studied the performance and the structural behavior of this type of concrete such as Ouchi et al. , Su et al.  and Burak  "
ABSTRACT: The cyclic behavior of RCS connection consisted of Reinforced Concrete (RC) columns and Steel (S) beams is studied in this paper. Two interior connections are investigated experimentally. The joint of the first specimen is designed according to ASCE 1994 guideline, while the second specimen has a new proposed joint detail. Self-consolidating concrete is used in both specimens. Self-consolidating concrete could improve constructability of the congested joint of RCS frames. The specimens detail include steel band plates, face bearing plates, L-shaped joint stirrups, and steel doubler plate for the panel zone. The proposed joint detail consists of additional bearing plates, which cause an increase in bearing & joint shear strength. Based on the experimental results, the behavior of both specimens was ductile and maintained their strength at high story drifts. This means that, RCS frames can be used in high seismic zones. By comparing the performance of two specimens, it is observed that using additional bearing plates, increases bearing and shear strength of the joint. Additionally, the inelastic force-deformation response of both specimens is simulated using the OpenSees software by taking into consideration the joint shear and bearing distortions. A modified method for modeling this type of connection is introduced and verified with experimental results.Journal of Constructional Steel Research 11/2015; 114:204–216. DOI:10.1016/j.jcsr.2015.07.026 · 1.37 Impact Factor
[Show abstract] [Hide abstract]
- "Make sure the average particle diameter is smaller than 6.5 mm – LCPC  430 50 170 847 825 – Particle–matrix model  Flow resistance ratio between 0.6–0.8 – – Su et al.  >270 – – Sand to total aggregates ranges from 50% to 57%, total aggregate ranges from 59% to 68% "
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
[Show abstract] [Hide abstract]
- "Unusual construction circumstances in Japan in the 1980s incited a team of engineers to develop a smart concrete material, which was later named as self-consolidating concrete (SCC). SCC possesses the ability to take form shapes and pass flow through congested reinforcement bars without any mechanical aid, thus eliminating the risk of concrete honeycombing and other defects resulting from poor compaction . As a result of its phenomenal fluidity, SCC easily flows through obstructions and narrow sections to fill-in the forms by its self-weight, yet free of any objectionable segregation or bleeding. "
ABSTRACT: Self-consolidating concrete (SCC) is a concrete material possessing an ability to take formwork shapes and pass through congested reinforcement bars without being vibrated, making it a ‘smart concrete’ material. However, the high cost of SCC resulting from the use of mineral fillers and high cement content has been a main factor impeding the widespread use of this smart material. Consequently, there is a need to investigate the use of low cost materials in the production of SCC to ensure adoptability of SCC in concrete construction. This paper presents the results of a study conducted to develop and evaluate the performance of four SCC mixtures using different combinations of filler materials, such as silica fume, natural pozzolana and metakaolin, in conjunction with limestone powder. The developed SCC mixtures exhibited high strength (compressive, tensile, bond and elastic modulus), excellent shrinkage behavior and good durability characteristics (high corrosion resistance and related indices). The findings of this study indicated the possibility of producing cost-effective and high-performance SCC mixtures using the mineral fillers considered in this study.Construction and Building Materials 10/2014; 68:268–276. DOI:10.1016/j.conbuildmat.2014.06.096 · 2.27 Impact Factor