Self Compacting Of Concrete Using GGBS
Published on Feb 27, 2019
Concrete technology has made tremendous strides in the past decade. The development of specifying a concrete according to its performance requirements, rather than the constituents and ingredients has opened innumerable opportunities for producers of concrete and users to design concrete to suit their specific requirements. One of the most outstanding advances in the concrete technology over the lastdecade is “self-compacting concrete” (SCC). Self-compacting concrete is a highly flowable, stable concrete which flows readily into places around congested reinforcement, filling formwork without any consolidation and Significant segregation. The hardened concrete is dense, homogeneous and has the same engineering properties and durability as that oftraditional vibrated concrete. The use of SCC eliminates the need for compaction thereby saves time, reduces labor costs and conserves energy. Furthermore use of SCC enhances surface finish characteristics.
Extensive studies have been made on Self Compacting Concrete with different combinations of mineral and chemical admixtures. However, Limited studies were done on the behavior of SCC with GGBS, and its efficiency. Considering this gap in existing literature an attempt has been made to study the strength efficiency of GGBS in SCC along with their mechanical strength and durability aspects.
Keywords : Self compaction of concrete, GGBS,Mix proportion, Flow Rate, Filling ability and passing ability , V- funnel test, L- box test, J Ring test, hardened properties Compressive strength.
1. To find out the basic properties of materials such as -
a) Coarse aggregate
b) Fine aggregate
c) Mineral Admixtures :GGBS
d) Chemical Admixtures:
2. To economic design of SCC by partial replacement of cement by GGBS for the targeted compressive strength.
3. To conduct laboratory test on designed SCC, On Fresh concrete and Hardened concrete of designed SCC.
Experimental investigation are carried at three different phases:
Phase 1: To determine basic properties of materials:
a. Coarse aggregate
Impact value of aggregates, Abrasion test, shape and size test
Crushing value of aggregates, water absorption test
Specific gravity of aggregates
b. Fine aggregate (M-SAND):
Size and grading, silt content test, specific gravity test.
Specific gravity test, fineness test, normal consistency, initial setting test.
Master Glenium 8633
f. Fresh concrete:
Slump flow test, J – Ring test,V funnel test, L box test.
g. Hardened concrete:
Compression test on concrete cubes, split tensile
Phase 2: Design mix of SCC as per IS Standard Code books.
Phase 3: To find mechanical properties of concrete, compressive strength of cast and cured concrete specimen for 7, 14,28days.
Results and Conclusion :
1. It has been verified, by using the slump flow, L box test and other tests on fresh SCC that self-compacting concrete (SCC) achieved consistency and self-compatibility under its own weight, without any external vibration or compaction.
2. The addition of GGBS mixes has shown improved performance in terms of strength and durability in all grades of SCC .This is due to the presence of highly reactive silica in GGBS.
3. Studies indicated that there is a good compatibility between mineral combinations GGBS along with the chemical admixtures. And acts as a good binder and improves the finishing of the concrete surface.
4. Experimental studies on efficiency of GGBS Combination in SCC confirmed the enhanced performance in terms of both strength and durability aspects with respect to performance of GGBS alone in SCC.
5. It is observed that there is an increase in the peak compressive strength for different SCC mixes made with GGBS. The increase is due to high reactivity with GGBS.
6. Addition of GGBS control the initiation of micro cracks, Improve the first crack load, the ultimate load and ductility of SCC. They are also effective in resisting deformation.
7. The strength loss and weight loss observed to be less in mixes with GGBS.
Project Done By Ms. Inchara R, Ms. Kavyashree D.C, Mr. Keerthi Kumar