Size Effect Study on Self Compacting Concrete

Size Effect Study on Self Compacting Concrete

Kunjan M. Patel

Civil Engineering Department Chhotubhai Gopalbhai Patel Institute of Technology

Bardoli, Gujarat, India.

Gunvant R. Solanki

Civil Engineering Department Chhotubhai Gopalbhai Patel Institute of Technology

Bardoli, Gujarat, India.

Dimple Desai

Civil Engineering Department Chhotubhai Gopalbhai Patel Institute of Technology

Bardoli, Gujarat, India.

Abstract Concrete is the construction material widely used throughout the world. Construction materials used in the industry should be friendly with the environment during its usage. Self-compacting concrete (SCC) 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. The hardened concrete is dense, homogenous and has the same engineering properties and durability as traditional vibrated concrete. In order to obtain the properties of fresh concrete for SCC, proportion of mineral and chemical admixtures to be added. A review is presented based on the development of self-compacting concrete with mineral and chemical admixtures. Compiled test data revealed distinct difference in mechanical properties of normal and high strength self compacting concrete. To understand the behaviour of Self Compacting Concrete, it is necessary that several factors be taken into account for designing the mix proportions. Strength of concrete, type of cement, type of aggregate, water cement ratio, type of admixture are some of the important factors that affect the performance of concrete. KeywordsSoft storey, Shear wall, Storey drift, Storey displacement, Storey shear, Time period, Time history analysis, Response spectrum analysis, ETABS.

1. INTRODUCTION

   Self-consolidating concrete (SCC) represents one of the most outstanding advances in concrete technology during the last two decades. Due to its specific properties, SCC may contribute to a significant improvement of the quality of concrete structures and open up new fields for the application of concrete like improved understanding of particle packing even at nanosacles.

   SCC was first developed in 1986 by Okamura to address durability concerns. (Okamura H. and Ouchi M, 2003). SCC can be defined as a flowing concrete without segregation and bleeding, capable of filling spaces and dense reinforcement or inaccessible voids without hindrance or blockage. (Khayat K.

   H. and Monty H, 1999).

   SCC offers many benefits to the construction practice which are simplicity in placement in complicated formwork and congested reinforcement, reduced construction times, especially at large construction sites, reduced noise pollution (since no vibrators are required), higher and more homogenous concrete quality across the entire concrete cross- section, especially around the reinforcement, concreting deep

   elements in single lifts, concreting at higher levels of tall buildings, improved surfaces and finishes and typically higher early strength of the concrete formwork can be removed quickly.

2. REVIEW OF LITERATURE

1. General

   Bertil Persson (2001) carried out an experimental and numerical study on mechanical properties, such as strength, elastic modulus, creep and shrinkage of self- compacting concrete and the corresponding properties of normal compacting concrete. The study included eight mix proportions of sealed or air-cured specimens with water binder ratio (w/b) varying between 0.24 and 0.80. Fifty percent of the mixes were SCC and rests were NCC. The age at loading of the concretes in the creep studies varied between 2 and 90 days. Strength and relative humidity were also found. The results indicated that elastic modulus, creep and shrinkage of SCC did not differ significantly from the corresponding properties of NCC.

   Nan Su et al (2001) proposed a new mix design method for self-compacting concrete. First, the amount of aggregates required was determined, and the paste of binders was 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 super plasticizer 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 indicated that the proposed method could be used to 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.

   Bouzoubaa and Lachemi (2001) carried out an experimental investigation to evaluate the performance of SCC made with high volumes of fly ash. Nine SCC

   mixtures and one control concrete were made during the study. The content of the cementitious materials was maintained constant (400 kg/m3), while the water/cementitious material ratios ranged from 0.35 to

   0.45. The self-compacting mixtures had a cement replacement of 40%, 50%, and 60% by Class F fly ash. Tests were carried out on all mixtures to obtain the properties of fresh concrete in terms of viscosity and stability. The mechanical properties of hardened concrete such as compressive strength and drying shrinkage were also determined. The SCC mixes developed 28-day compressive strength ranging from 26 to 48 MPa. They reported that economical SCC mixes could be successfully developed by incorporating high volumes of Class F fly ash.

   Hajime Okamura and Masahiro Ouchi (2003) addressed the two major issues faced by the international community in using SCC, namely the absence of a proper mix design method and jovial testing method. They proposed a mix design method for SCC based on paste and mortar studies for super plasticizer compatibility followed by trail mixes. However, it was emphasized that the need to test the final product for passing ability, filling ability, flowability and segregation resistance was more relevant.

2. Design of Reinforcement Beam

TABLE I. DESIGN DATA OF REINFORCEMENT DETAILS

1. RESULTS AND DISCUSSION

   In this study, fresh and hardened properties of SCC were investigated for different volume of binder (450-500 Kg/m³) and W/B ratio (0.29-0.34 by weight) with corresponding variation in the paste volume. The paste volume was varied from 350 liter to 450 liter. The replacement of cement by fly ash in binder were also constant for all mixes proportions (cement: fly ash= 70:30). Also, doses of super plasticizer were kept constant for all mixes proportion (SP=0.5%of weight of binder). The ability of SCC for compacting under its own weight is generally the main subject of such studies according to appropriate criteria given by the EFNARC committee (EFNRC; 2002). In the present study, such properties of SCC produced, and were investigated for all proportion. For selected proportion of mixes, cubes and beams were casted. The cubes were tested for compression after 28 days of curing under compressive testing machine having 200 tone capacities. The beams were tested under four point loading, and load vs. Deflection curve were prepared. The deflection was measured with the help of dial gauge having list count 0.001 mm. The beams were tested in digital universal testing machine having capacity 60 tones.

   TABLEII. RESULT OF S.C.C.BEAM

   Designation Beam	Maximum load Kn	Maximum displacement mm
   Small	33.560	3.2
   Medium	76.890	4.4
   Large	148.360	6.1

   40

   30

   20

   10

   0

   0 0.6 1.1 1.6 1.8 2.2 2.5 3.2

   Displacement x10-3 mm

   Load,KN

   Load,KN

   Fig.1 Small Size beam of SCC without fibre

   200

   150

   100

   50

   0

   0 1.2 1.9 2.5 2.9 3.2 3.7 4.1 4.8 5.6 6.1

   Displacement x10-3 mm

   Fig.2 Large Size beam of SCC without fibre

   Load,KN

   Load,KN

   200

   150

   100

   50

   0

   0 1.2 1.9 2.5 2.9 3.2 3.7 4.1 4.8 5.6 6.1 6.8

   Displacement x10-3 mm

   100

   80

   60

   40

   20

   0

   0 0.5 0.8 1.6 1.9 2.1 2.5 2.9 3.1 3.6 4.1 4.4

   Displacement x10-3 mm

   Designation BEAM	Maximum load KN	Maximum displacement mm
   Small	35.870	3.1
   Medium	79.980	4.9
   Large	165.760	6.8

   Fig.3 Medium Size beam of SCC without fibre TABLE III Result of SCC with glass fibers Beam (Pt = 1%)

   40

   30

   20

   10

   0

   0 0.6 1.1 1.6 1.8 2.2 2.5 3.1

   Displacement x10-3 mm

   Load,KN

   Fig. 4 Small Size beam of SCC with Glass fibre

   Fig. 5 Medium Size beam of SCC with Glass fibre

   Fig.6 Large Size beam of SCC with Glass fibre

   TABLE IV Result of SCC with Steel fibers Beam (Pt = 1%)

   Designation BEAM	Maximum load KN	Maximum displacement mm
   Small	39.780	3.3
   Medium	89.232	5.1
   Large	196.872	7.5

   50

   40

   30

   20

   10

   0

   0

   0.6 1.1 1.6 1.9 2.2 2.5 3

   Displacement x10-3 mm

   3.3

   Load,KN

   Load,KN

   Fig.7 Small size beam

   100

   80

   60

   40

   20

   0

   0 0.5 0.8 1.6 1.9 2.2 2.5 2.9 3.1 3.6 4.1 4.6 4.9 5.1

   Displacement x10-3 mm

   Fig.8 Medium size beam

   Load,KN

   250

   200

   150

   100

   50

   0

   0 1.2 1.9 2.5 2.7 3.2 3.7 4.1 4.8 5.6 6.1 6.9 7.5

   Displacement x10-3 mm

   Fig.9 Large size beam

2. CONCLUSION

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.

Self compability is depending on work ability of concrete. Indirectly its depend on ingredients of concrete like cement, sand and aggregate. Its also depend on dosage of super plasticizer and water binder ratio.

In my experiment it was observed that as binder quantity increase the workability of concrete was also increase.

It was happened due to increase in fine materials in total volume of concrete. Also I can conclude that for same binder quantity if increase water binder ratio. The workability of concrete was also increase.

The self compacting concrete is very sensitive concrete with respect change in water quantity.

I conclude that addition of steel fibre and glass fibre are increasing the strength of concrete.

In my project i use Glass Fiber and without glass fiber (SCC) Concrete, after that I conclude strength of glass fiber concrete is more than SCC concrete about 10% to 20%.

I use Steel Fiber and without Steel fiber (SCC) Concrete, after that we conclude strength of Steel fiber concrete is more than SCC concrete about 30% to 40%.

I conclude that strength of Steel fiber concrete is more than Glass fiber concrete.

ACKNOWLEDGEMENT

I have taken efforts in this paper. However, it would not have been possible without the kind support of Prof. Gunvant R. Solanki and Prof. Dimple Desai. I would like to extend my sincere thanks to all of them. I am highly indebted for their guidance and constant supervision as well as for providing necessary information. I would like to express my gratitude towards my parents for giving encouragement which helped me a lot. My thanks and appreciations also go to my college (CGPIT) for providing continuous support.

REFERENCES

1. BertilPersson, A comparison between mechanical properties of self-compacting concrete and the corresponding properties of normal concrete, Cement and Concrete Research, 31,2001,pp 193-198.

2. Nan Su, Kung-Chung Hsu and His-Wen Chai, A simple mix design method for self-compacting concrete, Cement and Concrete Research, 31 ,2001, pp 17991807.

3. N. Bouzoubaa and M. Lachemi, Self-compacting concrete incorporating high volumes of class F fly ash Preliminary results, Cement and Concrete Research, 31, 2001, pp 413-420.

4. Dr. R. Sri Ravindrarajah, D. Siladyi and B. Adamopoulos, Development of High-Strength Self-Compacting Concrete with reduced Segregation Potential, Proceedings of the 3rd International RILEM Symposium , Reykjavik, Iceland, 17-20 August 2003, Edited by O. Wallevik and I. Nielsson , (RILEM Publications), 1 Vol., 1048 pp., ISBN: 2-912143-42-X, soft cover.

5. Hajime okamura and Masahiro ouchi, Self Compacting Concrete, Journal of Advanced Concrete Technology, volume 1, 2003, pp 5-15.

6. Mohammed Sonebi, Medium strength self-compacting concrete containing fly ash: Modelling using factorial experimental plans, Cement and Concrete Research, 34, 2004, pp 11991208.

7. Mustafa Sahmaran, Heru Ari Christianto and Ismail OzgurYaman, The effect of chemical admixtures and mineral additives on the properties of self-compacting mortars, Cement & Concrete Composites, 28,2006,pp 432440.

8. Mustafa Sahmaran and I. OzgurYaman, Hybrid fiber reinforced self-compacting concrete with a high-volume coarse fly ash, Construction and Building Materials, 21, 2007, pp 150156.

9. BurakFelekoglu, SelcukTurkel and BulentBaradan, Effect of water/cement ratio on the fresh and hardened properties of self- compacting concrete, Building and Environment, 42, 2007,pp 17951802.

10. BinuSukumar, K. Nagamani and R. SrinivasaRaghavan, Evaluation of strength at early ages of self-compacting concrete with high volume fly ash, Construction and Building Materials, 2007, pp 1-8