A STUDY ON HIGH PERFORMANCE CONCRETE WITH FLY ASH AND SILICA POWDER S.KARTHICK PAANDIAN G.ILAMPARITHI K.KASI D.MANOJ KUMAR GUIDED BY: Ms.KARTHIYAINI M.E., Asst. Prof. (Sr. Grade)

OBJECTIVES The main objective of this project is to compare the compressive strength of conventional concrete cubes with concrete cubes made by using fly ash and silica powder as a admixture.

MATERIALS USED Cement(43 grade) OPC. Fine aggregate. Coarse aggregate of 12mm. Water both for mixing as well as curing. Silica powder Fly Ash

SPECIFIC GRAVITY OF MATERIALS Sp. Gravity Cement = 3.15 Coarse Aggregate (12mm) = 2.65 Fine Aggregate = 2.61 Silica powder = 2.5 Fly Ash = 2.19

FLY ASH Fly ash is the mineral residue produced by burning coal that is captured from exhaust gases and collected for use. Fly ash produces more cementitious paste. It has a lower unit weight Fly ash reduces the amount of sand needed in the mix to produce workability

Advantages of fly ash Reduces the water demand. Greater resistance to sulphate attack Minimizes cracking due to thermal and drying shrinkage Long term mechanical properties (compressive, flexural, abrasion strength) improved Workability of fresh concrete is easily enhanced

Uses of fly ash Partial replacement for ordinary portland cement (OPC) Percentage of fly ash in total cementing materials, normally ranges from 15 to 25% It can go up to 30-35% in some applications

SILICA POWDER Silica powder is a natural stone form mineral that is grinded in crystalline form Physical properties Appearance: White Fine Powder Sp. gravity: 2.5

Uses of silica powder Plastics: Most preferred mineral in PVC chappal, PVC pipes and industrial products Rubber: Widely used in high value rubber products industry. These are also used in distempers, emulsion paints, architectural finishes, flat paints traffic paints, industrial primer, undercoats, putties and finishes Paints: Versatile application in paint convenient filler in paper manufacture Also used in soft boards

MIX RATIO Water: Cement: F.A.: C.A. = 0.4: 1: 1.65: 2.92

Aggregates Aggregates are the materials basically used as filler with binding materials in the production of mortar & concrete. TYPES OF AGGREGATES Coarse Aggregate (grit) Fine Aggregate (sand)

MIXING

CUBES

TESTING OF CUBES

TESTING OF CUBES

TESTING OF CUBES

COMPRESSIVE STRENGTH (7 DAYS) MPa RESULTS OBTAINED SO FOR M40 GRADE MIX COMPRESSIVE STRENGTH (7 DAYS) MPa Sample1 Sample2 Sample3 Average CONTROL 29.08 27.24 28.51 28.27 SILICA POWDER 5% 28.71 28.53 27.72 28.32 SILICA POWDER 10% 26.46 25.53 25.19 25.72 SILICA POWDER 15% 24.31 25.73 23.01 24.35

RESULTS OBTAINED FOR M40 GRADE MIX COMPRESSIVE STRENGTH (7 DAYS) MPa Sample1 Sample2 Sample3 Average CONTROL 29.08 27.24 26.51 27.61 5% OF FLY ASH and SILICA 28.73 29.63 28.15 28.53 10%OF FLY ASH and SILICA 29.22 28.36 27.55 28.37 15%OF FLY ASH and SILICA 29.32 28.65 29.10 29.35

COMPRESSIVE STRENGTH (28 DAYS) MPa RESULTS OBTAINED FOR M40 GRADE MIX COMPRESSIVE STRENGTH (28 DAYS) MPa Sample1 Sample2 Sample3 Average CONTROL 59.78 57.70 57.45 58.31 SILICA POWDER 5% 56.76 54.34 55.12 55.40 SILICA POWDER 10% 55.63 55.82 54.70 55.35 SILICA POWDER 15% 52.78 51.63 53.24 52.55

COMPRESSIVE STRENGTH (28 DAYS) MPa RESULTS OBTAINED FOR M40 GRADE MIX COMPRESSIVE STRENGTH (28 DAYS) MPa Sample1 Sample 2 Sample3 Average CONTROL 59.78 57.70 57.45 58.31 5% OF FLY ASH and SILICA 58.26 58.93 57.41 58.20 10%OF FLY ASH and SILICA 57.92 58.16 56.28 15%OF FLY ASH and SILICA 57.38 57.85 58.49 57.90

CONCLUSION In our study we have made samples of M40 grade concrete cubes of dimension 100 mm x 100 mm x 100mm ratio of mix design were 1:1.65:2.92 were designed according to the IS code method. A addition of 5%, 10%, 15% of silica and fly ash were added to the normal grade of concrete mix and above cubes are further casted. These cubes were tested for compression strength on 7 days and 28 days from the casting.

These compressive strength of the specimen were compared with one another and final output shows that there is slight reduction in compressive strength when it is added with silica and fly ash. These reduction may be due to addition of these admixtures. Hence these admixtures can be used as a replacement of Silica as a fine aggregates and Fly ash as a cement in the future works. These results were concluded from our study.