Performance of Self-Compacting Concrete Containing Different Mineral Admixtures

P. Ramanathan,I. Baskar,P. Muthupriya,R. Venkatasubramani 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.2

Self-Compacting Concrete is an innovative concrete that does not require vibration for placing and compaction. It is able to flow under its own weight, completely filling formwork and achieving full compaction, even in the presence of congested reinforcement. One of the disadvantages of self-compacting concrete is its cost, associated with the use of high volumes of Portland cement and use of chemical admixtures. One alternative to reduce the cost of self-compacting concrete is the use of mineral admixtures such as silica fume, ground granulated blast furnace slag and fly ash, which is finely, divided materials added to concrete during mixture procedure. When these mineral admixtures replace a part of the Portland cement, the cost of self-compacting concrete will be reduced especially if the mineral admixtures are waste or industrial by-product. Moreover, the use of mineral admixtures in the production of selfcompacting concrete not only provides economical benefits but also reduces heat of hydration. The incorporation of mineral admixtures also eliminates the need for viscosity-enhancing chemical admixtures. The lower water content of the concrete leads to higher durability, in addition to better mechanical integrity of the structure. This paper presents an experimental investigation on strength aspects like compressive, flexural and split tensile strength of self compacting concrete containing different mineral admixtures and workability tests for different mineral admixtures (slump, L-box, U-box and T50) are carried out. The methodology adopted is that mineral admixtures are replaced by 30%, 40% and 50% for Portland cement and performance is measured and compared. The influence of mineral admixtures on the workability, compressive strength, splitting tensile strength and flexural strength of self-compacting concrete was investigated. The mix proportion is obtained as per the guidelines given by European Federation of producers and contractors of special products for structure. The following inferences were made; optimum dosage of super plasticizer enhanced the flow property of the concrete. As a result, overall improvements in the flow and filling ability of the self-compacting concrete were observed. It is observed that when mineral admixtures used in self-compacting concrete, can reduce the amount of super- plasticizer necessary to achieve a given fluidity. It should be noted that the effect of mineral admixtures on admixture requirements is significantly dependent on their particle size distribution as well as particle shape and surface characteristics. From this view point, a cost effective self-compacting concrete design can be obtained by incorporating reasonable amounts of silica fume, fly ash, and ground granulated blast furnace slag.

Performance of concrete structures with a combination of normal SCC and fiber SCC

Kianoosh Farhang,Hamoon Fathi 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.20 No.6

Fiber reinforced concretes exhibit higher tensile strength depending on the percent and type of the fiber used. These concretes are used to reduce cracks and improve concrete behavior. The use of these fibers increases the production costs and reduces the compressive strength to a certain extent. Therefore, the use of fiber reinforced concrete in regions where higher tensile strength is required can cut costs and improve the overall structural strength. The behavior of fiber reinforced concrete and normal concrete adjacent to each other was investigated in the present study. The concrete used was self-compacting and did not require vibration. The samples had 0, 1, 2 and 4 wt% polypropylene fibers. 15 cm sample cubes were subjected to uniaxial loads to investigate their compressive strength. Fiber Self-Compacting Concrete was poured in the mold up to 0, 30, 50, 70 and 100 percent of the mold height, and then Self-Compacting Concrete without fiber was added to the empty section of that mold. In order to investigate concrete behavior under bending moment, concrete beam samples with similar conditions were prepared and subjected to the three-point bending flexural test. The results revealed that normal Self-Compacting Concrete and Fiber Self-Compacting Concrete may be used in adjacent to each other in structures and structural members. Moreover, no separation was observed at the interface of Fiber Self-Compacting Concrete and Self-Compacting Concrete, either in the cubic samples under compression or in the concrete beams under bending moment.

The Laboratory Experiment of the Effect of Quantity and Length of Plastic Fiber on Compressive Strength and Tensile Resistance of Self-Compacting Concrete

Mohsen Oghabi,Mehdi Khoshvatan 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.8

Self-compacting concrete (SCC) is known as a high-performance concrete that molds by its weight and without the need for vibration or impact and easily crosses the small spaces between the rebars. Various additives have been used in recent research to construct the self-compacting concrete in order to achieve higher strengths and improved performances. Because of the utilization of self-compacting concrete in bulk concreting like dams, silos, and tanks, the optimized use for reducing the final costs of the project is important and essential. A fundamental question in improving the fiber self-compacting concrete behavior is that what is the optimum amount of fiber addition for low fiber concentrations. In this research, the effect of the addition of fiber with concentrations lower than 1,000 gr (100, 250, 500, and 1,000 gr) on the self-compacting concrete behavior with different fiber lengths have been studied. This research examined the effect of the quantity and length of recycled plastic fiber on the compressive strength and tensile resistance of self-compacting concrete. Slump flow experiment L box and sieve and compressive and tensile strength experiment were done on samples. In this study, 13 plans of concrete mixing were surveyed with ratio of water to cement 0.4. One plan without fiber was chosen as a reference sample and 12 self-compacting concrete with plastic Fibers were made in the laboratory with dimensions of 1, 2, 3 cm with their amounts equal 100, 250, 500 and 1,000 g/m3. Laboratory results showed that increasing the amount and length of fibers led to decreased flowability and passability plus increased detachment in samples. By increasing plastic fibers, compressive strength increased by 8.4% and tensile resistance increased by 4.22%. Their elevation depends on fibers amount. Fiber length did not affect the compressive strength and tensile resistance very much. The increase was such that the tensile strength increased by about 100% and 200% as the length increased from 1 to 2 cmand 1 to 3 cm, respectively. The 1 cm plastic fiber length could be selected as the optimum length for increasing the compressive strength by considering the efficiency.

Optimization of Mix Proportion of Self-compacting Concrete Based on Single Fluid Model

Xiuzhi Zhang,Chong Zhang,Mengdi Bi,Haibo Yang,Hailong Sun,Ru Mu 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.3

The study aims to optimize the mix proportion of self-compacting concrete according to the workability and compressive strength. Firstly, based on computational fluid dynamics, the flowability and filling ability of self-compacting concrete were simulated by the single-fluid model to verify the single-fluid model. And then, the simulation of casting a pre-cambered composite beam was carried out. In the end, the mix proportion was optimized considering the filling ability and the compressive strength of self-compacting concrete. The results showed that increasing sand rate can improve the workability and decrease the rheological parameters of self-compacting concrete. The mixture with a 45% sand ratio in the case of 3% silica fume alone or 43% sand ratio in the case of 30% granulated blast furnace slag and 3% silica fume had adequate filling ability and excellent long term compressive strength. Moreover, the model can be used to simulate the filling ability and passing capacity of self-compacting concrete and the maximum error between the simulation results and the actual measured value is 4.80%. When the concrete mixture is considered to be uniform, namely, without considering the effect of the aggregates, the single-fluid model can simulate the casting of self-compacting concrete.

Rheological Properties of Binder Pastes for Self-Compacting Concrete

Park, Yon-Dong Korea Concrete Institute 2001 KCI concrete journal Vol.13 No.1

This paper investigated rheological properties of binder pastes for self-compacting high performance concrete. Six mixtures of self-compacting concrete were initially prepared and tested to estimate self-compacting property. Then, the binder pastes used in self-compacting concrete were tested for rheological properties using a rotary type rheometer. Binder pastes with different water-binder ratios arid flow values were also examined to evaluate their rheological characteristics. The binders were composed of ordinary Portland cement, fly ash, two types of pulverized blast-furnace slag, and limestone powder. The flow curves of binder pastes were obtained by a rotary type rheometer with shear rate control. Slump flow, O-funnel time, box, and L-flow teats were carried out to estimate self-compacting property of concrete. The flow curves of binder pastes for self-compacting concrete had negligible yield stresses and showed an approximately linear behavior at higher shear rates beyond a certain limit. Test results also indicated that the binders incorporating fly ash are more appropriate than the other types of binders in quality control of self-compacting concrete.

Self compacting reinforced concrete beams strengthened with natural fiber under cyclic loading

Prasad M.L.V,Prasenjit saha,P.R.Kumar 사단법인 한국계산역학회 2016 Computers and Concrete, An International Journal Vol.17 No.5

The present work focuses on the use of coconut fiber in self compacting concrete. Self- Compacting Concrete (SCC) is a highly flowable, stable concrete which flows readily into place, filling formwork without any consolidation and without undergoing any significant segregation. Use of fibers in SCC bridge the cracks and enhance the performance of concrete by not allowing cracks to propagate. They contribute to an increased energy absorption compared to plain concrete. Coconut fiber has the highest toughness among all natural fibers. It is known that structures in the seismic prone areas are always under the influence of cyclic loading. To justify the importance of strengthening SCC beams with coir fiber, the present work has been undertaken. A comparison is made between cyclic and static loading of coconut fiber reinforced self compacting concrete (FRSCC) members. Using the test data obtained from the experiment, hysteresis loops were drawn and comparison of envelope curve, energy dissipation, stiffness degradation were made and important conclusions were draw to justify the use of coconut fiber in SCC.

Self-compacting light-weight concrete; mix design and proportions

Behnam Vakhshouri,Shami Nejadi 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.1

Utilization of mineral and chemical admixtures in concrete technology has led to changes in the formulation and mix design in recent decades, which has, in turn, made the concrete stronger and more durable. Lightweight concrete is an excellent solution in terms of decreasing the dead load of the structure, while self-compacting concrete eases the pouring and removes the construction problems. Combining the advantages of lightweight concrete and self-compacting concrete is a new and interesting research topic. Considering its light weight of structure and ease of placement, self-compacting lightweight concrete may be the answer to the increasing construction requirements of slender and more heavily reinforced structural elements. Twenty one laboratory experimental investigations published on the mix proportion, density and mechanical properties of lightweight self-compacting concrete from the last 12 years are analyzed in this study. The collected information is used to investigate the mix proportions including the chemical and mineral admixtures, light weight and normal weight aggregates, fillers, cement and water. Analyzed results are presented in terms of statistical expressions. It is very helpful for future research to choose the proper components with different ratios and curing conditions to attain the desired concrete grade according to the planned application.

Self-Compacting Concrete Using Marble Sludge Powder and Crushed Rock Dust

M. Shahul Hameed,A. S. S. Sekar,L. Balamurugan,V. Saraswathy 대한토목학회 2012 KSCE JOURNAL OF CIVIL ENGINEERING Vol.16 No.6

Self Compacting Concrete (SCC) has had a remarkable impact on the concrete construction industry, especially the precast concrete industry. Crushed Rock Dust (CRD) and Marble Sludge Powder (MSP) are discarded in the nearby land and the natural fertility of the soil is spoiled. MSP and CRD can be used as filler and helps to reduce the total voids content in concrete. Consequently, this contributes to improve the strength of concrete. An experimental investigation has been carried out to study the combined effect of addition of MSP and CRD on the strength and durability of SCC. The study on physical, chemical and mechanical properties such as compressive strength and split tensile strength and the durability tests include water absorption test, water permeability, rapid chloride permeability; electrical resistivity and half cell potential are carried out in this study. From the results it is confirmed that compressive strength increases with increase in percentage replacement of MSP up to 15% of CRD in place of FA. It is found that split tensile strength is directly proportional to the compressive strength. The highest electrical resistivity values were obtained for Normal Concrete with 100% CRD and significant increase in resistivity values for SCC. Self Compacting Concrete (SCC) has had a remarkable impact on the concrete construction industry, especially the precast concrete industry. Crushed Rock Dust (CRD) and Marble Sludge Powder (MSP) are discarded in the nearby land and the natural fertility of the soil is spoiled. MSP and CRD can be used as filler and helps to reduce the total voids content in concrete. Consequently, this contributes to improve the strength of concrete. An experimental investigation has been carried out to study the combined effect of addition of MSP and CRD on the strength and durability of SCC. The study on physical, chemical and mechanical properties such as compressive strength and split tensile strength and the durability tests include water absorption test, water permeability, rapid chloride permeability; electrical resistivity and half cell potential are carried out in this study. From the results it is confirmed that compressive strength increases with increase in percentage replacement of MSP up to 15% of CRD in place of FA. It is found that split tensile strength is directly proportional to the compressive strength. The highest electrical resistivity values were obtained for Normal Concrete with 100% CRD and significant increase in resistivity values for SCC.

The Evaluation of the Influence of Mineral Additives on the Durability of Self-Compacting Concretes

Zdzis awa Owsiak,Wioletta Grzmil 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.4

The physical, mechanical and rheological properties of self-compacting concretes enable their application in the construction of bridges which are structures particularly vulnerable to the processes of carbonation and cyclic freezing and thawing. The technology of self-compacting concrete requires an increase in high powder content in the concrete mix, which is obtained by the application of mineral additives. The paper presents test results of the physical and mechanical properties of self-compacting concrete with cement with mineral additives and of the microstructure of its surface layer. The objective of the tests was to evaluate the influence of mineral additives (limestone powder, siliceous fly ash and blast-furnace slag) on the durability of the surface layer of self-compacting concrete subjected to accelerated carbonation and the freeze-thaw process in the presence of de-icing salts. The microstructure of the surface layer of the carbonated concrete was less compact, which was confirmed by the increased surface water absorption and water penetration in the layer in comparison with the non-carbonated concrete. Moreover, carbonated concrete exhibited more significant surface scaling when compared to non-carbonated concrete.

Optimal Mixture Proportion for High Performance Concrete Incorporating Ground Granulated Blast Furnace Slag

최재진,김은겸,유정훈 한국콘크리트학회 2005 콘크리트학회논문집 Vol.17 No.3

In this study, a mix design for self compacting concrete was based on Okamuras method and concrete incorporated just a ground granulated blast furnace slag. Replacement ratio of slag is in the range of 20-80% of cement matrix by volume. For the optimal self compactability in mixture incorporating ground granulated blast furnace slag, the paste and mortar tests were first completed. Then the slump flow, elapsed time of 500mm slump flow, V funnel time and filling height by U type box were conducted in concrete. The volume of coarse aggregate in self compacting concrete was in the range of 50-60% to the solid volume percentage of coarse aggregate. Finally, the compressive and splitting tensile strengths were determined in the hardened self compacting concrete incorporating ground granulated blast furnace slag. From the test results, it is desirable for self compacting concrete that the replacement of ground granulated blast furnace slag is in the range of 40-60% of cement matrix by volume and the volume of coarse aggregate to the solid volume percentage of coarse aggregate with a limit of 55%.