An Experimental Investigation on Mechanical and Durability Properties of High Strength Fiber Reinforced Concrete

Transcription

1 International Journal of cientific reearch and management (IJSRM) Volume 3 Iue 12 Page Webite: ISSN (e): An Experimental Invetigation on Mechanical and Durability Propertie of High Strength Fiber Reinforced Concrete A.Lekhya 1 and Dr. B. Damodar Reddy 2 1 Student, SVCET (Autonomou), Jawaharlal Nehru Technological Univerity, Anantapur, India. lekhya03@gmail.com 2 Aociate Profeor, Dept of Civil Engg, SVCET, Jawaharlal Nehru Technological Univerity, Anantapur, India. damu2007@gmail.com ABSTRACT: At preent a large cale production of cement i ueful for contruction which caue global warming on one ide and depletion of natural reource on other ide. So that different pozzolanic material like ilica fume, Fly ah, are ued in concrete a admixture. The preent tudy wa to evaluate the mechanical and durability propertie of M60 grade concrete by replacing 10%, 15% of ilica fume and 10%, 20%, 30% of fly ah to cement. 0.5% teel hook fiber are ued by volume fraction a admixture for all proportion of HSFRC. The main objective of the preent work i to develop M60 grade concrete and to find the effective doage of ilica fume and fly ah. Thi paper preent the detailed experimental tudy on compreive trength at different age i.e. 3, 7, 28, 56, 90 and plit tenile tet and flexural trength at the age of 28. Durability tet like Rapid Chloride Permeability tet and Water Aborption tet were conducted on cated pecimen. Key ward: Silica Fume (SF), Fly Ah (FA), Steel Hook Fiber (SHF), High Strength Concrete (HSC), High Strength Fiber Reinforced Concrete (HSFRC), Compreive Strength, Split Tenile Strength, Flexural Strength, RCPT. I. Introduction With the paage of time to meet the demand, there wa a continual earch in human being for the development of high trength and durable concrete. The hitory of high trength concrete (HSC) i about 35 year old, in late 1960 the invention of water reducing admixture lead to the high trength precat product and tructural element were cat in itu uing high trength concrete (HSC). The primary difference between high-trength concrete (HSC) and normal-trength concrete (NSC) relate to the compreive trength that how the maximum reitance to concrete ample to applied preure. Although there i no precie point of eparation between high-trength concrete and normal-trength concrete, the American Concrete Intitute (ACI) define high-trength concrete a concrete with a compreive trength greater than 60MPa.. The utilization of fine Pozzolanic material in hightrength concrete (HSC) like ilica fume and fly ah lead to reduction in ize of the crytalline compound, particularly, calcium hydroxide. Conequently, there i a reduction of the thickne of the interfacial tranition zone in hightrength concrete. Application of mineral admixture uch a ilica fume (SF), fly ah (FA) in concrete are effective and eay to future increae in the trength and make durable for high trength concrete. The addition of admixture to the concrete mixture increae the trength by pozzolanic action and filling the mall void and that are created between cement particle. Almot all thee concrete have mineral additive involve for a variety of reaon including trength improvement, reduction of permeability, higher crack reitance and durability factor. Thi tudy decribe the development of high trength fiber reinforced concrete (HSFRC) with f'ck in the range of N/mm 2. The objective of preent tudy wa mainly to increae the compreive trength, plit tenile trength and flexural trength, with the aim of producing a concrete requiring le teel for ue in the contruction of pretreed concrete bridge upertructure. In addition to increaing compreive trength of the concrete and uing fiber reinforcement to improve compreive trength, another development objective wa to increae veratility by producing HSFRC that doe not requiring pecial material or pecial curing method. The addition of high trength teel fiber to the concrete increae flexural trength and ductility propertie of concrete. Thi reidual trength alo A.Lekhya 1 IJSRM volume 3 iue 12 Dec 2015 [ Page 3791

2 tend to reduce crack ize and pacing. The ue of teel fiber i particularly attractive for high-trength concrete, which can be relatively brittle without fiber. In the preent tudy, the different admixture were ued to tudy their combined effect on the reitance of concrete in addition to their effect on durability, compreive trength, plit tenile trength and flexural trength by partial replacement of mineral admixture by 10%, 15% of ilica fume &10%, 20% and 30% of fly ah by the weight of cement with a contant amount of 0.5% teel hook fiber are added by volume fraction of concrete, throughout the tudy. 2.0 Experimental Program 2.1 Material Cement Ordinary Portland cement of (Zuari brand) 53 grade wa elected for the experimental invetigation. The characteritic of cement were teted a per IS: and IS: (9). The experiment uch a finene, tandard conitency, initial etting time, final etting time and pecific gravity of cement are conducted on ordinary Portland cement hown in table 1. Table-2.1: propertie of opc S. No Characteritic of cement Value 1 Finene of cement 6% 2 Normal conitency 33% 3 Initial etting Time 40 minute 4 Final etting time 350 minute 5 Specific gravity fine aggregate Sand i a naturally occurring material from Rock and Mineral by weathering and i compoed of majorly io 2, and Calcium carbonate. The pecific particle ize compoition of the and a per the IS 650:1966 and IS 383:1970 wa ued. River and wa ued for the experimental work. The propertie of fine aggregate are hown in Table 2. Table-2.2: Propertie Of Fine Aggregate S.no Propertie Reult 1. Specific gravity Bulking of and 4% 4 Water aborption 1% 5 Bulk Denity 1460 kg/m 3 6 Finene modulu oand Coare Aggregate 2.8 Gravel are popularly ued a Coare aggregate, which are free from organic impuritie and ilt. Locally available aggregate of paing through 20 mm ieve and retained on 10 mm ieve are taken. A per Indian tandard pecification IS the coare aggregate were teted and mentioned in table 3. Table-2.3: Coare Aggregate Propertie S.No Propertie Reult 1. Specific gravity Finene Modulu Water Aborption 0.5% 5 Bulk Denity kg/m 3 6 Elongation index 20.49% 7 Flakine index 13.19% Silica Fume Silica fume i a wate by-product of the production of ilicon and ilicon alloy. It i available in different form, of which the mot commonly ued i in a dandified form. Silica fume ued wa conforming to IS: 1331(PART- 1) 1992 and alo ASTM C ( ). Silica fume wa alo referred a micro ilica or condened ilica fume, i a byproduct material that i ued a a pozzolanic. Thi by product i a reult of the reduction of high-purity quartz with coal in an electric arc furnace in the manufacture of ilicon or ferroilicon alloy. In thi project ilica fume i ued a partial replacement to cement and it propertie are mentioned in table 4. Table-2.4: Propertie Of Silica Fume Property Reult Color Dark grey Practical ize <1µm Specific urface 15,000 to 30,000 m 2 /kg Bulk denity 695 g/cm 3 Specific gravity 2.2 Moiture content 0.78% Sio % Al2o3 0.69% *A per manufacturer manual Fly Ah For thi project Fly ah i taken from Rayalaeema thermal power plant (RTPP), Kadapa. Fly ah conform to the requirement of IS: 3812 part-i and alo ASTMC-618 type-f were ued. Table 2.5 Propertie Of Fly Ah Sl. No. Characteritic Percentage 1 Silica,SiO A.Lekhya 1 IJSRM volume 3 iue 12 Dec 2015 [ Page 3792

3 2 Alumina,Al 2 O Iron oxide,fe 2 O Lime, CaO Magneia, MgO Sulphur trioxide, SO Lo of ignition Surface area,(m 2 /kg) Specific gravity 2.3 The pecimen of tandard cube of (150mm x 150mm x 150mm) and tandard cylinder of (300mm x150mm) and Prim of (100mm x100mm x 500mm) were ued to determine the compreive trength, plit Tenile trength and flexural trength of concrete. For each proportion of ilica fume replacement, 10%, 20% and 30% fly ah i replaced to cement and a contant amount of 0.5% teel hook fiber are added for all proportion HSFRC. The contituent were weighed and the material were mixed by hand mixing. The water binder ratio (W/B) (Binder = Cement + Partial replacement with ilica fume and fly ah) adopted wa The cated pecimen were cured in water at room temperature and then teted for it compreive trength, plit tenile and flexural trength a per Indian Standard Steel Hook Fiber Steel fibre make ignificant improvement in flexure, impact and fatigue trength of concrete. Thee fibre are ued in concrete a crack arreter and would ubtantially improve it tatic and dynamic propertie. Compreive trength of fibre reinforced concrete increaed with increae in teel fibre content. The addition of hear trength increae ignificantly. Steel hook fiber compliance to the requirement of ASTM A 820 (type-1 cold drawn wire) Table-2.6: Propertie Of Steel Hook Fibre 1 Type Hooked end 2 Diameter of fiber 0.60 mm 3 Length of fiber 30 mm 4 Apect ratio (L/D) 50 A per ASTM Yield Strength of Wire : > 1000 MPa Wire Mechanical Propertie Tenile trength of the wire : 1450 Mpa Strain at failure : < 4 % Shape The ending hape of Hooked End Steel Fiber are very important to grant adheion between fiber and concrete. 3.0 MIX-PROPORTIONS 3.1 Mix Proportion: Water Cement Fine aggregate Coare aggregate Proportion by Weight (kg/m 3 ) Proportion by Ratio Experimental Procedure Silica fume (%) TABLE-3.2: MIX-PROPORTIONS FOR M60 GRADE CONCRETE THAT ARE USED IN HSFRC Fly Ah (%) F.A (kg/m 3 ) C.A (kg/m 3 ) W/C Ratio Water (liter) Steel fiber (% by volume of concrete) 0% 0% % 10% 15% 10% % 20% % 30% % 10% % 20% % 30% % TEST METHODS 3.31 Mechanical Propertie Mechanical propertie uch a compreive trength, plit tenile trength and flexural trength tet are evaluated Compreive Strength Tet A.Lekhya 1 IJSRM volume 3 iue 12 Dec 2015 [ Page 3793

4 Compreive trength tet uually give an overall picture of the quality of concrete becaue trength i directly related to the tructure of the hydrated cement pate. The compreion tet i an important concrete tet to determine the trength development of the concrete pecimen. Compreive trength tet were performed on the cube pecimen at the age of 3, 7, 28, 56 and 90. The compreive trength tet reult are mentioned in table Splitting Tenile Strength The indirect method of applying tenion in the form of plitting wa conducted to evaluate the effect of ilica fume and fly ah on tenile propertie of concrete. The plit tenile trength i a more reliable technique to evaluate tenile trength of concrete (lower coefficient of variation) compared to other method. The plit tenile trength of 150 mm diameter and 300 mm high concrete cylindrical pecimen wa determined to ae the effect of ilica fume and fly ah on the tenile propertie of the concrete. The plit tenile trength tet reult are mentioned in table Flexural Strength The ultimate flexural trength analyi preented in thi paper i baed on the conventional compatibility and equilibrium condition ued for normal reinforced concrete except that the contribution of the fiber in the tenion i recognized.. The Flexural trength tet reult are mentioned in table DURABILITY TESTS Rapid Chloride Permeability Tet The rapid chloride penetration tet i carried out a per AASHTO T277, (ASTM C1202) tet. In thi a wateraturated, 50-mm thick, 100-mm diameter concrete pecimen i ubjected to a 60 V applied DC voltage for 6 hour uing the apparatu. In one reervoir i a 3.0 % NaCl olution and in the other reervoir i a 0.3 M NaOH olution. The total charge paed i determined and thi i ued to rate the concrete. The procedure of thi tet method for meauring the reitance of concrete to chloride ion penetration ha no bia becaue the value of thi reitance can be defined only in term of a tet method. The method relie on the reult from a tet in which electrical current pae through a concrete ample during a ix-hour expoure period. The interpretation i that the larger the Coulomb number or the charge tranferred during the tet, the greater the permeability of the ample. The more permeable the concrete, the higher the coulomb the le permeable the concrete, the lower the coulomb. The method ha hown good correlation with chloride tet [10]. The following formula, baed on the trapezoidal rule can be ued to calculate the average current flowing through one cell. Q = 900(I0+2I30+2I60+2I90+2I I300+2I330+I360) Where, Q = current flowing through one cell (coulomb) I0 = Current reading in ampere immediately after voltage i applied, and It = Current reading in ampere at t minute after voltage i applied The table 3-2 how the rating of chloride permeability according to ASTM C [10]. Charge Paed Chloride Ion Penetrability (Coulomb) > 4000 High Moderate Very < 100 Negligible The main objective of thi tet wa to evaluate the performance of mixe and compared with each other. Chloride ion penetrability tet were conducted on 100mm diameter and 50mm thick cylinder pecimen for each concrete mixture 28 for M60 grade of concrete. The reult of chloride permeability in coulomb for different proportion of concrete are given in Table Water Aborption Tet One of the mot important propertie of a good quality concrete i low-permeability, epecially one reitant to freezing and thawing. The water aborption tet i carried out at the age of 28 according to tandard procedure ASTM C For the water aborption tet, 100 x 200mm ize of cylinder i cut into three part (top, middle, bottom) of 50mm thickne and 100mm diameter, then pecimen are dried in an oven at 100 o to 110 o C for not le than 24 hour. After removing each pecimen from the oven, allow it to cool in dry air to a temperature of 20 o to 25 o C and determine the ma.. The percentage water aborption tet reult are mentioned in table Reult and Dicuion Reult of hardened concrete with partial replacement of ilica fume and fly ah with 0.5% teel hook fiber are dicued in Comparion with normal concrete. 4.1 Compreion Tet Table-4.1: compreive trength of high trength frc concrete with 0.5% teel hook fibre a admixture: A.Lekhya 1 IJSRM volume 3 iue 12 Dec 2015 [ Page 3794

5 S.N O SAMPLES 3 Controlled mix %SF+10%FA+0 10%SF+20%FA AVERAGE COMPRESSIVE STRENGTH (N/mm 2 ) % SF+10% FA+ 0.5% 10% SF+20% FA+ 0.5% 10% SF+30% FA+ 0.5% 15% SF+10% FA+ 0.5% 15% SF+20% FA+ 0.5% 15% SF+30% FA+ 0.5% %SF+30%FA DAYS SPLIT TENSILE STRENGTH %SF+10%FA+0 15%SF+20%FA %SF+30%FA CC S10F10 S10F20 S10F30 S15F10 S15F20 S15F30 0.5% of teel fiber Fig N0 4.1: Compreive Strength Comparion of All Proportion of Concrete 4.2 Split Tenile Tet Day 0 CC DAYS 7 DAYS 28 DAYS 56 DAYS 90 DAYS Table-4.2: plit and flexural tet reult Average plit Flexural Cae tenile trength trength (MPa) (Mpa) Controlled mix Fig: Tenile trength at 28 for variou percentage of Silica Fume and Fly Ah DAYS FLEXURAL STRENGTH CC S10F10 S10F20 S10F30 S15F10 S15F20 S15F30 0.5% of teel fiber Fig 6.11: Flexural trength at 28 for variou percentage of Silica Fume and Fly Ah From above graph it ha been een that, the comparion of flexural trength reult of concrete for variou replacement of ilica fume and fly ah with 0.5% teel hook fiber a admixture. At 10% ilica fume and 20% fly ah give maximum 28 plit trength a 5.2N/mm2, next A.Lekhya 1 IJSRM volume 3 iue 12 Dec 2015 [ Page 3795

6 higher value occur at 15% ilica fume and 10% fly ah with 0.5% teel hook fiber a N/mm Durability Tet S.no Table 4.3: rapid chloride penetration tet: I I average cumula Penetrab. in SAMPLE tive ility of coulo in chloride mb ma 1 CC Medium S.no 10%SF+10%FA+0 10%SF+20%FA+0 10%SF+30%FA+0 15%SF+10%FA+0 15%SF+20%FA+0 15%SF+30%FA І Table4.4: water aborption tet reult: Sample Wet weight (kg) Dry weight (kg) Very Very Very Water aborption in % 1 CC S10F S10F S10F S15F S15F S15F Concluion Baed on the reult obtained from the preent invetigation the following concluion were made; 1. By the addition of teel hook fiber in concrete lead to increae in compreive trength and make concrete into ductile. 2. In plit tenile and flexural tet, we notice that crack width reduced due to the preence of teel fiber when compared with conventional pecimen. 3. When the cement i replaced with 10% ilica fume and 20% fly ah give the optimum compreive trength, plit tenile trength and flexural trength. 4. At 10% ilica fume and 20% fly ah replacement to cement, compreive trength were increaed up to 20.34% when compared with conventional concrete for At 10% ilica fume and 20% fly ah replacement to cement, plit tenile trength were increaed up to 60.85% when compared with conventional concrete for At 10% ilica fume and 20% fly ah replacement to cement, flexural trength were increaed up to 38.74% when compared with conventional concrete for The addition of ilica fume and fly ah a replacement to cement, it normal conitency and initial etting time increae with increae in percentage and final etting time decreae with increae in percentage. 8. The ue of mineral admixture in concrete caue coniderable reduction in the volume of large pore at all age and thereby reduce the permeability of concrete mixe becaue of it high finene and formation of C-S-H gel Reference 1) Gambhir M.L., Concrete Technology, McGraw Hill Education (India) Private Limited, New Delhi, ) Indian Standard method of tet for trength of concrete are: , Bureau of Indian Standard, New Delhi. 3) Santhakumar, A.R., Concrete Technology, Oxford pre, New Delhi, ) Mehta P. and Aitcin (1995), Development in the application of high performance concrete, Chapter 17 Univerity of Memphi 5) Indian tandard code of practice for pecification for coare and fine aggregate from natural ource of concrete IS: , Bureau of Indian tandard, New Delhi. 6) Indian tandard code of practice for recommended guideline for concrete mix deign IS: , Bureau of Indian tandard, New Delhi. 7) Indian tandard code of practice for plain and reinforced concrete IS: , Bureau of Indian Standard, New Delhi. 8) P.K. Mehata: (Concrete International 17/97), Durability Critical iue for the future. A.Lekhya 1 IJSRM volume 3 iue 12 Dec 2015 [ Page 3796

7 9) P.K.mehta (2005): High-Performance, High volume Fly ah Concrete for utainable Development. Author Profile DOI: /ijrm/v3i12.03 A.Lekhya, Received the B.Tech in Civil Engineering and M.Tech in Structural Engineering degree from Jawaharlal Intitute of Technology Anantapuramu in 2013and 2015, repectively A.Lekhya 1 IJSRM volume 3 iue 12 Dec 2015 [ Page 3797