Nur Adibah Ayuni Binti Abd Malek Universiti Malaysia Perlis, Malaysia
CONTENT ■ INTRODUCTION ■ LITERATURE REVIEW ■ METHODOLOGY ■ RESULT AND DISCUSSION ■ CONCLUSION
INTRODUCTION
BACKGROUND OF STUDY ■ High igh pe perfor orma mance nce fiber iber rein inforced ced co concr ncrete( e(HPFR HPFRC) C) can can be be ap applied plied as as repai epair ma materia ial becau ecause se of of it its prope operti ties es which which is is low pe permea meabil ility ity and and it it out outstan standin ing mecha mechanica ical prope perti ties es that may be be lead to to increa easi sing ng the adhesion sion forces ces bet etween een the concret ncrete over layers. ■ In In recen ecent resear esearch, ch, resea esearche cher use use a sur urface ace prepar eparat ation ion me metho thod and and it it sho showed ed tha that sur surface ace preparat ation ion give the best st bond nd strength ngth result ■ Cu Curin ing can can al also so im improve ul ulti tima mate com compr press essiv ive st stren ength, gth, im impr proves es resistan esistance ce to to abra abrasion sion and and red educe uce sur surface ace dustin dusting. Curing Curing al allows ws mor more water to to be be mad ade avai ailable able for the the hyd ydrat ration ion reacti tion on of of concr crete cemen ent paste that will leads ds to to bett etter er strength ngth of of concr cret ete
PROBLEM STATEMENT ■ HPFR FRC C propose posed d to be used d as repair ir material erial for det eterior eriorati ation on of concrete e structu ructure re ■ A bo bond nd strengt rength h bet betwee een n old and nd ne new conc ncrete e is ne necessar ssary y to be be a good bond stren rengt gth ■ Curin ring g and surface ce prepara paratio tion n metho ethod d help p to achieve excelle cellent nt bond stren rength gth bet etween een HPFR FRC with h the surfac ace e of normal rmal concrete
OBJECTIVE To s study dy the effect of surface ace preparatio aration n meth ethod d (sandb ndblasting, asting, grooves, , drill l holes) on the bond strength th betwee etween n normal al concret ete and HPFR FRC To study dy the effect of two wo different ent curing ng meth ethod d (ambient bient curing, ng, wa water r curing ing) ) on the bond stre reng ngth th betwee etween n norm rmal al concret rete and d HPFR FRC
LITERATURE REVIEW
CURING METHOD Steam curing
SURFACE PREPARATION Author hor Title Key Remark k Tayeh, B. A., Abu Bakar, B. Evaluation of bond strength • As cast without • Sand blast has highest slant shear H., Megat Johari, M. A., & between normal concrete roughening (AC), strength Voo, Y. L. (2013a). substrate and ultra high • Sand blasting (SB), • Sand blasting specimen has acceptable performance fiber concrete as a • Wire brushing(WB) bond strength according to The ACI repair material. • Drill holes (DR) Concrete Repair Guide • Grooves (GR) Safritt, M. (2015). Bond Interface Strength between • As cast without • Sandblasting has highest slant shear Ultra High Performance Concrete roughening strength and splitting tensile strength and Normal Concrete • Sandblasting • Etched with hydrochloric acid. Al-Hallaq (2014) Bond, I., Between, S., & Over, C. • casting substrata • Scabbling method has highest split (n.d.). Improving Bond Strength surface against tensile test and slant shear test. Between Concrete Over Layers steel formwork • mechanical wire brush for 10 min/m2 • Scarifying • Scabbling Júlio, E. N. B. S., Branco, F. Concrete-to-concrete bond • cast against steel • Result of slant shear test shows sand formwork A. B., & Silva, V. D. (2014). strength. Influence of the blast has highest slant shear strength • surface prepared with roughness of the substrate among the others. steel brush surface. • surface partially chipped • surface partially chipped plus water saturation 24hours • surface treat with sand blast.
Bond strength between normal concrete and HPFRC Author hor Title Remar ark k Tayeh, B. A., Bakar, B. H. A., Mechanical and permeability properties Properties of UHPFRC is low permeability and it outstanding Johari, M. A. M., & Lei, Y. (2012) of the interface between normal mechanical properties, have advanced and built up a core concrete substrate and UHPFC overlay idea of using UHPFC to restore and strengthen zones where structures are presented to high mechanical loadings and in addition on account of extreme natural presentation conditions Hussein, L., & Amleh, L. (2015). Structural behavior of ultra-high UHPFRC and normal strength concrete/high strength performance fiber reinforced concrete- concrete bond strength between them was considerably normal strength concrete or high high without addition of shear connector. UHPFRC has very strength concrete composite members high strength and very low permeability compared to normal strength concrete that make its suitable for be a new repair material Askar, L. K., Tayeh, B. A., & Effect of Different Curing Conditions on UHPFRC has an outstanding mechanical and durability Bakar, B. H. A. (2013)., the Mechanical Properties of UHPFC, make it ideal for developing new solution to pressing concern on highway deterioration, repair and replacement and it widely used nowadays. It shows that UHPFRC has a good bond strength with normal concrete
SLANT SHEAR TEST Slant nt shear r strength( gth(MPa) MPa) Surfac face e As cast without Grooved Drill Holes Sandblast Wire Brush HCI etched preparat aration ion roughening Referen rences es Tayeh eh et et al al., 2013 8.39 13.63 11.99 17.74 12.15 - Tayeh eh et et al al., 2012 12 8.68 13.92 12.27 17.81 12.75 - Saffr frit it 2015 11.96 - - 14.68 - 11.89
SPLITTING TENSILE TEST Split it tensile le strength(MPa) gth(MPa) Surface face prepar aration ation As cast without Sandblasting Wire brush Grooved Drill hole HCI Etched roughening Referen rences es Tayeh eh et et al al., 2013 1.82 3.68 2.77 3.11 2.50 - Tayeh eh et et al al., 2012 1.85 3.24 2.60 3.79 2.96 - Saffr frit it, 2015 20.92 35.74 - - - 9.56
METHODOLOGY
FLOWCHART Literature review Preparation for Normal concrete Surface preparation for NC Sandblasting Drill Hole Grooved Water Curing Water Curing Water Curing Casting UHPFRC Casting UHPFRC Casting UHPFRC and NC and NC and NC Ambient curing Water curing Ambient curing Water curing Water curing Ambient curing 6sample 6sample 6sample 6sample 6sample 6sample Slant shear & splitting tensile test Discuss the best bond strength between NC & UHPFRC
MIX PROPORTION FOR NORMAL CONCRETE Material rial Course e Fine e Po Portland land Water Aggre gregat gate Aggre gregat gate Cement t Propor ortion tion 590 1090 470 235 (kg) for 1 𝑛 3 MIX PROPORTION FOR HPFRC Constitue ituent Type of of material rial Propor ortion( tion(kg) g) Propor orti tion on Po Portland land cemen ent Type CEM1- strength class 12 (kg) for 24.19 44.69 19.27 9.64 52.5R 0.041 𝑛 3 Fine aggregat egate 150-300 𝜈𝑛 0.6 300-600 𝜈𝑛 . 1.5 Water Potable water 2.4 Superp erplas lasti ticizer er polycarboxylate ether 0.6 based (PCE) Silic ica fume Micro Silica 6.0 Steel fiber er 6mm 1.21 14mm 0.4
Prismatic beam 100mm x100mm x 300mm Cylinder 100mmx 200mm
Sandblasting Grooved Drill Hole Grooved Drill Hole Sandblasting
Preparation of HPFRC Fine sand size 300-600 𝜈𝑛 Silica fume Sand 150-300 𝜈𝑛 and cement Steel fiber 6mm & 14mm Superplasticizer Water
Testing Slant Shear Test Splitting Tensile Test ASTM-C822 (1999). Standard ASTM C496: Splitting Tensile Test Method for Bond Strength of Strength of Cylindrical Concrete Epoxy-Resin System Used with Specimens Concrete by Slant Shear
RESULT AND DISCUSSION
Bond Strength Between Normal Concrete and HPFRC ■ Slant t Shear Strengt ngth Surfac face e Curing ng method hod Sample le Shear r Stress Average verage 𝑇 𝑏𝑤 Failure lure mode treatme tment S(MPa Pa) (MPa) a) Grooved ed Water curing GV1 11.32 C GV2 13.30 C (WC) 12.30 GV3 12.28 C Air Curing (AC) GV1 13.66 C GV2 7.90 C 10.64 GV3 10.35 C Drill ll hole Water curing DH1 12.46 B DH2 9.20 C (WC) 10.90 DH3 11.05 C Air Curing (AC) DH1 10.84 B DH2 6.03 B 9.29 DH3 11.00 C Sandblas blast t Water curing SB1 15.94 C SB2 13.02 C (WC) 15.16 SB3 16.51 D Air Curing (AC) SB1 16.29 C SB2 10.02 C 11.42 SB3 7.96 C
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