- Open Access
- Total Downloads : 132
- Authors : T. Soundharya , V. Karthikeyan
- Paper ID : IJERTV6IS100157
- Volume & Issue : Volume 06, Issue 10 (October 2017)
- DOI : http://dx.doi.org/10.17577/IJERTV6IS100157
- Published (First Online): 27-10-2017
- ISSN (Online) : 2278-0181
- Publisher Name : IJERT
- License: This work is licensed under a Creative Commons Attribution 4.0 International License
Self Compacted Concrete Beams-Flexural Resistance by Partial Replacement of Cement with Ground Granulated Blast Furnace Slag
1T. Soundharya, 2V. Karthikeyan 1Assistant Professor, 2 Assistant Professor 1Civil Engineering
1K.Ramakrishnan College of Technology, Trichy, Tamilnadu
Abstract Self compacting concrete has the property of flowing and compacting due to its own weight. Since compacting of concrete in the presence of grid locked reinforcements are increasing, the need for self flowing concrete is felt very much. Meanwhile Ground Granulated Blast Furnace slag (GGBS) is an effective alternate to cement which contains cement material. In this study, self compacting concretes were considered using GGBS by replacing Portland cement with 10%, 20%, 30%, 40% and 50% by weight. The rheological and mechanical properties of SCG (GGBS incorporated SCC) were found to be increased compared to conventional concrete. Six reinforced concrete beams (SCGB) of shear span to depth ratio (a/d) 2 were tested for flexural capacity and ductile behavior. The experimental cracking moment of SCGB beams were found to be more than the theoretical cracking moment enhancing its flexural resistance. The outcomes show that the use of GGBS in SCC enables higher performance with economy and sustainability.
Index Terms Self Compacting Concrete, GGBS, Flexural Resistance, Ductile Behavior.
Self compacting concrete (SCC) is defined as a concrete that produce a high deformation with good segregation
resistance. The SCC is distinguished by its high fluidity, passing ability and cohesiveness characteristics that eliminate or reduce to a minimum the need for mechanical compaction. The self-compacting concrete can reach self- leveling work performance in the fresh state by relying on the action of gravity, there is no need of applying external vibrations in construction sites, which improve the quality of concrete placing and can save time and labour needed in the construction sites. Hence in the last 15 years, SCC has been widely used around the world for its constructive ability and higher durability.
Cement and Aggregates
Ordinary Portland cement of 53 grade conforming to IS 12269:1987 with specific gravity of 3.15 was used. River sand obtained from Thoothukudi and the locally available blue metal crushed stone aggregates of size 20mm were used as fine and coarse aggregates respectively. Their specific gravity, bulk density, percentage of water absorption and fineness modulus were obtained as per IS 2386:1963 and shown in Table 1.
Table 1 Properties of Aggregates
Water absorption (%)
Bulk density (kg/m3) 1629 1563
GGBS (Ground Granulated Blast furnace Slag), obtained from JSW Cement Limited, Thoothukudi and conforming to IS 12089:1987 was used as the mineral admixture. The
physical and chemical properties of GGBS used for this study is given in Table 2.
Table 2 Properties of GGBS
JSW GGBS (%)
Loss on ignition
Glass content (%)
Fineness of GGBS
Specific gravity of GGBS
Potable water with pH 7 was used.
The Ceraplast 300 RS(G) of sulphonated naphthalene formaldehyde condensates (SNF) type superplasticizer was used to increase the workability of self-compacting concrete at fresh state given in Table 3.
Table 3 Properties of SNF type superplasticizer
Specific gravity (30C)
pH (10% solution)
Sodium sulphate content
The mix design was prepared for M30 grade SCC as per ACI guidelines based on the effect of GGBS as binary blended cement. Based on the strength obtained from trial mix given in Table 4, the actual mix was formulated. The type of mix was established by the combination of powder and Viscosity Modifying Admixture (VMA) which is prepared by increasing powder content i.e. GGBS and using VMA i.e. superplasticizer. The concrete mix proportions of GGBS incorporated SCC here after designated as SCG were as shown in Table 5. The SCG mixes with 0%, 10%, 20%, 30%, 40% and 50% GGBS were termed as SCG0, SCG10, SCG20, SCG30, SCG40 and SCG50 respectively.
Figure 5 were found to decrease by 0.003%, 2.4%,
4.9%, 5.8%, 7.5% and 27.18%, 30.23%, 35.74%,
14.25%, 16.73% with the replacement of 10%, 20%,
30%, 40%, 50% GGBS to SCC respectively. Bouzoubaa et al has reported that increase in percentage of fly ash decreases the slump flow, the same holds good for GGBS also as shown in Table 6 and Figure 2. It is clearly evident from Table 6 and Figure 3 that the time taken by the SCG mixes to flow through the V- funnel decreases by 1.7%, 0.01%, 1.7%, 0.01% with replacement of 10%,
20%, 30%, 40% GGBS and increases by 0.01% with replacement of 50% GGBS in SCC respectively which is not in good agreement with O.R.
Table 4 Trial Mix
Designation of mix
Cementitious binder by weight
Water content by
weight of cement
Percentage of SP by volume of
Compressive strength at the age
of 28 days (N/mm2)
Table 5 Validation of Mix design
Designation of mix
Water content by weight
Percentage of SP by volume of
The rheological properties of SCG mixes were found using slump test, V- funnel test, L – box test and U – box test as per EFNARC recommendations and seen through Figure 1.
150 Ã— 150 Ã— 150 mm cubes were prepared for checking compressive strength using SCG mixes and tested in a universal testing machine at 7, 28 and 56 days respectively. The average of three specimens is the reported strengths.
RESULTS AND DISCUSSION Table 6 Fresh Concrete properties
Slump flow (mm)
650 – 800
V-funnel test (sec)
6 – 12
0.8 – 1
0 – 30
Figure 1. a) Slump flow test b) V- Funnel test c) L-Box test d) U- Box test
Figure 2 Slump flow of SCG mixes Figure 3 Filling ability of SCG mixes from V- funnel
Figure 4. Passing ability of SCG mixes from L box Figure 5 Passing ability of SCG mixes from U box
Table 7 Compressive strength of SCG beams
Compressive strength (N/mm2)
7th day 28th day 56th day SCG50
Age of concrete
Figure 6 Compressive strength of SCG mixes
FLEXURAL CAPACITY OF SCG BEAMS
Figure 7 Reinforcement cage
Figure 8 Beam reinforcement outline
Figure 9 Test setup sketch
Figure 10 Experimental test set up
Crack pattern and failure mode of control beam
Figure 11 Crack pattern of control beam
The initial crack and the final crack in the control beam specimen were noticed for the loading of 3T and 11.5T respectively. The control beam is failed by developing diagonal crack in the shear region which extended up to
the middle fibre as seen in Figure 11.
Crack pattern and failure mode of SCG beams
Figure 12 Crack pattern of SCG beams
Table 8 Initial and Final crack load of SCG beams
Initial crack load (T)
Final crack load (T)
14 11.5 12.5 12.5 11.5
6 4 3.5 4 3.75 3.5
SCG 0 SCGB10SCGB20SCGB30SCGB40SCGB50
Various combinations of mix
Initial crack load
Figure 13. Initial and final crack load of SCG beams
Moment carrying capacity
Table 9 Theoretical and Experimental cracking moment
Mcr (theoretical) (kNm)
Mcr (experimental) (kNm)
Theoretical cracking moment Mcr (theoretical) (kNm)
4.18 Mcr Poly. (Mcr)
3.94 y = -0.0625×3 + 1.86×2 – 18.271x + 63.289
RÂ² = 0.8772
8.50 9.50 10.50 11.50
Experimental cracking moment
Mcr (experimental) (kNm) Figure 14 Cracking moment comparison
The R-squared value equals 0.8772, which is a best. Since it is closed to 1, it can be concluded that the experimental cracking moment is in depends with theoretical cracking moment.
The ductility of SCGB beams were analyzed theoretically using ductility factor (Âµ) which is the ratio of ultimate deflection (u) to yield deflection (y) as given in (3). Ultimate deflection is defined as the deflection
corresponding to the ultimate load and yield deflection is the deflection caused by the member during yielding.
Table 10 Ductility factor of SCG beams
Âµ = u/y
It is observed from Table 9 that ductility factor of SCGB10, SCGB20, SCGB30 were 19.0%, 20.2%, 17.78% higher than conventional concrete where as SCGB40 and SCGB50 were 1.25% and 3.45% lesser than conventional concrete.
The use of GGBS as partial replacement for OPC in SCC not only reduces the CO2 emission from OPC but also produce the mechanical and rheological properties of SCC.
The workability of Self Compacting Concrete found by slump decreases with increase in percentage of GGBS, the time of flow through the V- funnel test time decreased with addition of GGBS in SCC and the blocking ratio obtained from L- box was found to be satisfactory up to 30% replacement of OPC with GGBS in SCC.
At the 7 days, the compressive strength of SCG10 and SCG20 were found to drop by 5.58% and 18.91% while compressive strength of SCG30, SCG40 and SCG50 were enhanced by 4.02%, 10.17% and 0.01% respectively from conventional mix.
It was pointed that the compressive strength of SCG10, SCG20, SCG30, SCG40, SCG50 were reduced by 28.85%, 26.05%, 21.29%, 15.68% , 24.26% and improved by 3.39%, 3.89%, 5.67%, 8.79%, 6.25% at the age of 28 and 56 days respectively from conventional mix.
SCGB beams with higher percentage of GGBS exhibits higher ductility.
The experimental cracking moment of SCGB0, SCGB10, SCGB20, SCGB30, SCGB40 and SCGB50 is 54.46%, 65.21%, 60%, 64.78%, 61.78% and 59.64% higher than the theoretical cracking moment. This exhibits that the replacement of GGBS to OPC in SCC produces the flexural behavior of self compacting concrete beams.
Ductility factor of SCGB10, SCGB20, SCGB30 were 19%, 20.2%, 17.78% higher than conventional concrete where as SCGB40 and SCGB50 were 1.25% and 3.45% lesser than conventional concrete mix. Hence, it can be concluded that upto 30% replacement of GGBS to OPC in SCC is effective.
Bouzoubaa, M. Lachemi, Self-compacting concrete incorporating high volumes of class F fly ash Preliminary results, Cement and Concrete Research 31 (2001) pp.413-420
O.R. Kavitha, V.M. Shanth , G. Prince Arulraj, P. Sivakumar, Fresh, micro- and macrolevel studies of metakaolin blended self- compacting concrete, Applied Clay Science 114 (2015) pp.370 374
M.S.Shetty, Concrete Technology, Theory and Practice, S.Chand and company limited, New Delhi (2005)
Navid Ranjbar, Arash Behnia, Belal Alsubari, Payam Moradi Birgani, Mohd Zamin Jumaat, Durability and mechanical properties of self-compacting concrete incorporating palm oil fuel ash, Journal of Cleaner Production 112 (2016) pp.723-730.
Watcharapong Wongkeo, Pailyn Thongsanitgarn, Athipong Ngamjarurojana, Arnon Chaipanich, Compressive strength and chloride resistance of self-compacting concrete containing high level fly ash and silica fume, Materials and Design 64 (2014) pp.261269.
Delsye C. L. Teo, Md. Abdul Mannan, John V. Kurian, Flexural behaviour of reinforced lightweight concrete beams made with oil palm shell (OPS), Journal of Advanced Concrete Technology,
Volume 4 No.3 pp.459-468
S.P.Sangeetha, P.S.Joanna, Flexural behaviour of reinforced concrete beams with partial replacement of GGBS, American Journal of Engineering Research (AJER) Volume 03, Issue 01, pp.119-127
IS456:2000 Plain and Reinforced concrete – Code of practice, Bureau of Indian Standards, New Delhi.