Fiber-Reinforced Concrete For Structure Components (MPC-17 .

MPC 17-342 A. Ghadban, N. Wehbe and M. UnderbergFiber-Reinforced Concretefor Structure ComponentsA University Transportation Center sponsored by the U.S. Department of Transportation serving theMountain-Plains Region. Consortium members:Colorado State UniversityNorth Dakota State UniversitySouth Dakota State UniversityUniversity of Colorado DenverUniversity of DenverUniversity of UtahUtah State UniversityUniversity of Wyoming

Fiber-Reinforced Concrete for Structure ComponentsAhmad A. Ghadban, PhDPost-Doctoral Research AssociateDepartment of Civil and Environmental EngineeringSouth Dakota State UniversityBrooking, South DakotaNadim I. Wehbe, Ph.D., PEProfessor and Department HeadDepartment of Civil and Environmental EngineeringSouth Dakota State UniversityBrookings, South DakotaMicah UnderbergStructural Design EngineerKiewit EngineeringEnglewood, ColoradoDecember 2017

AcknowledgmentThe authors would like to acknowledge the financial support of the Mountain-Plains Consortium (MPC)and the South Dakota Department of Transportation for funding this study through project MPC-437.DisclaimerThe contents of this report reflect the views of the authors, who are responsible for the facts and theaccuracy of the information presented. This document is disseminated under the sponsorship of theDepartment of Transportation, University Transportation Centers Program, in the interest of informationexchange. The U.S. Government assumes no liability for the contents or use thereof.NDSU does not discriminate in its programs and activities on the basis of age, color, gender expression/identity, genetic information, marital status, national origin, participation in lawful offcampus activity, physical or mental disability, pregnancy, public assistance status, race, religion, sex, sexual orientation, spousal relationship to current employee, or veteran status, asapplicable. Direct inquiries to Vice Provost, Title IX/ADA Coordinator, Old Main 201, 701-231-7708, ndsu.eoaa@ndsu.edu.i

ABSTRACTConcrete infrastructures in cold areas such as South Dakota tend to experience early deterioration that ismostly triggered by steel corrosion. The corrosion is initiated by chloride penetration through cracks inthe concrete. Fiber reinforced concrete (FRC) is known to be a good alternative to conventional concretein cold areas due to its enhanced durability and resistance to crack development. There is little guidancefor SDDOT pertaining to the use and testing of FRC. There is also lack of information about new fiberproducts that have been introduced to the market in recent years. A comprehensive literature review, aswell as interviews with SDDOT and other DOT personnel, were carried out in this study to evaluate pastFRC experiences, effect of different factors on the properties of FRC, and existing FRC design andconstruction practices. The effect of fiber type and dosage on air content, slump, flexural strength,compressive strength, and impact resistance was examined by conducting laboratory experiments on FRCmixes incorporating five different fiber types and four different fiber dosages. While steel fibers hadsuperior performance, the results showed that among the synthetic fibers the fiber type did notsignificantly affect any of the FRC properties. Fiber dosage, however, affected the slump and the flexuralproperties. While the slump decreased, the flexural strength properties increased with increased fiberdosage. The results were also in good agreement with provided manufacturers’ claims. Of the foursynthetic fibers tested in this study, the most cost-effective were the Fibermesh 650 and FORTA-FERROfibers. Based on the experimental results and the literature, an FRC proportioning and selection guidelineswere developed.ii

TABLE OF CONTENTS1. INTRODUCTION. 11.1 Project Description. 11.2 Objectives . 12. LITERATURE REVIEW . 32.1 Introduction . 32.2 Fiber Types . 32.3 Fresh Concrete Properties . 72.3.1 Slump . 72.3.2 Air Content . 72.3.3 Fresh Unit Weight . 72.3.4 Concrete Temperature . 72.3.5 Fiber Distribution . 72.4 Hardened Concrete Properties . 82.4.1 Laboratory Testing . 82.4.1.1 Compressive Strength . 82.4.1.2 Tensile Strength . 82.4.1.2 Flexural Strength . 92.4.1.4 Average Residual Strength . 92.4.1.5 Toughness . 102.4.1.6 Impact Strength . 102.4.1.7 Fatigue Strength . 102.4.1.8 Freeze-Thaw Resistance. 112.4.1.9 Scaling Resistance. 122.4.1.10 Chloride Permeability . 132.4.1.11 Abrasion Resistance . 132.4.1.12 Bond Strength. 132.4.1.13 Shrinkage Cracking . 142.4.2 Field Testing . 152.4.2.1 Surface Inspections . 152.4.2.2 Bond Strength. 152.5 Structural Applications . 152.5.1 Mix Design . 152.5.2 Construction . 162.5.2.1 Bridge Decks . 172.5.2.2 Deck Overlays . 182.5.2.3 Jersey Barriers . 182.5.2.4 Approach Slabs . 182.5.3 Specifications . 192.5.3.1 South Dakota . 192.5.3.2 Georgia . 192.5.3.3 New York . 202.5.3.4 Texas . 202.5.3.5 Washington . 212.5.3.6 Summary . 21iii

3. SOUTH DAKOTA DOT INTERVIEWS . 223.1 Introduction . 223.2 Previous Experience. 223.3 Construction/Demolition. 243.3.1 Mixing and Placement. 243.3.2 Consolidation . 243.3.3 Finishing. 243.3.4 Curing. 243.3.5 Demolition . 253.4 Current/Future Practice . 253.5 Specifications . 263.5.1 Deck Overlay . 263.5.2 Pavement Repair . 263.5.3 Future Specifications. 263.6 Fiber Suppliers and Types . 274. OTHER STATE DOT INTERVIEWS . 284.1 Introduction . 284.2 Previous Experiences with FRC . 284.3 Preparation and Placement of FRC . 294.3.1 Mixing . 294.3.2 Placement . 304.3.3 Consolidation . 304.3.4 Finishing. 304.3.5 Curing. 304.3.6 Demolition . 314.4 Specifications . 314.5 Fiber Suppliers and Types . 325. METHODOLOGY . 345.1 Selection of Fibers . 345.2 Materials and Mix Design . 395.2 Laboratory Tests . 415.3.1 Sample Preparation . 415.3.1.1 Mixing . 415.3.1.2 Placement . 435.3.1.3 Consolidation . 445.3.1.4 Curing. 465.3.2 Fresh Concrete Testing . 485.3.2.1 Slump . 485.3.2.2 Air Content . 495.3.2.3 Fresh Unit Weight . 505.3.2.4 Concrete Temperature . 515.3.3 Hardened Concrete Testing . 515.3.3.1 Compressive Strength . 515.3.3.2 Flexural Performance . 535.3.3.3 Average Residual Strength . 565.3.3.4 Impact Strength . 575.3.3.5 Fiber Distribution . 595.3.3.6 Statistical Analysis . 59iv

6. EXPERIMENTAL RESULTS AND ANALYSIS . 616.1 Fresh and Hardened Properties . 616.2 Statistical Results . 636.3 Effect of Fiber Type . 646.3.1 Compressive Strength . 646.3.2 Flexural Performance . 676.3.3 Impact Strength . 706.4 Effect of Fiber Dosage . 716.4.1 Slump . 716.4.2 Flexural Performance . 736.4.3 Impact Strength . 786.5 Fiber Distribution. 807. FINDINGS AND CONCLUSIONS. 847.1 Literature Findings and Conclusions . 848. RECOMMENDATIONS . 878.18.28.38.48.58.6Fiber Type and Dosage . 87Design . 87Construction . 88Laboratory and Field Testing . 88Guidelines for FRC Material Selection, Mix Design, Construction, and Testing . 88Future Research . 899. REFERENCES . 90APPENDIX A: FRC CATALOG . 95APPENDIX B: SDDOT INTERVIEWEE LIST AND INTERVIEW GUIDE . 114APPENDIX C: STATE DOT INTERVIEWEE LIST AND INTERVIEW GUIDE . 119APPENDIX D: FIBER DATA SHEETS . 123APPENDIX E: CHEMICAL ADMIXTURES DATA SHEET . 134APPENDIX F: HARDENED CONCRETE PROPERTIES . 138APPENDIX G: GUIDELINES FOR FRC MATERIAL SELECTION, MIX DESIGN,CONSTRUCTION, AND TESING. 150v

LIST OF TABLESTable 2.1Table 2.2Table 2.3Table 2.4Table 2.5Table 3.1Table 3.2Table 3.3Table 3.4Table 4.1Table 4.2Table 5.1Table 5.2Table 5.3Table 5.4Table 5.5Table 5.6Table 5.7Table 6.1Table 6.2Table 6.3Table 6.4Table 8.1Table 8.2Table 8.3Table 8.4Table 8.5Abbreviated FRC Catalog . 6Rating scale for concrete scaling (Ostertag and Blunt, 2008) . 12Georgia DOT's qualified products list. 20New York DOT's acceptable list of fibers for concrete reinforcement . 20Summary of material requirements specified by other state DOTs . 21Percent of interviewees with previous experience with certain FRC applications . 22Percent of interviewees with previous experience with certain fibers . 23Proposed reasons for any increased cost during FRC applications . 23FRC applications recommended by the SDDOT interviewees . 25FRC applications that were discussed with interviewees from other DOTs . 28Illinois DOT’s “Approved Product List” for synthetic fibers for PCC pavementinlays or overlays . 33List of selected fibers for experimental evaluation . 34FRC mix design for all mixes . 39Proposed dosage rates for each fiber . 40Selected material tests . 41Number of lifts required for each experimental test. 44Number of vibrator insertions required per lift for each experimental test . 45Rate of net mid-span deflection to be used for flexural strength testing . 53Summary of fresh concrete properties . 62Summary of hardened concrete properties . 63F-test results . 64Comparison between measured and claimed equivalent flexural strength ratio . 76Recommendations for fiber type and dosage . 87Recommendations for FRC design . 87Recommendations for construction of FRC . 88Recommendations for laboratory and field testing of FRC . 88Recommendations for future FRC research . 89vi

LIST OF FIGURESFigure 2.1Figure 2.2Figure 2.3Figure 2.4Figure 2.5Figure 5.1Figure 5.2Figure 5.3Figure 5.4Figure 5.5Figure 5.6Figure 5.7Figure 5.8Figure 5.9Figure 5.10Figure 5.11Figure 5.12Figure 5.13Figure 5.14Figure 5.15Figure 5.16Figure 5.17Figure 5.18Figure 5.19Figure 5.20Figure 5.21Figure 5.22Figure 5.23Figure 5.24Figure 5.25Figure 6.1Figure 6.2Figure 6.3Figure 6.4Figure 6.5Figure 6.6An example of each of the four fiber categories, as specified by ASTM C1116 . 4Double dog-bone geometry of a uniaxial direct tensile test specimen (Chao et al., 2011) . 9Surfaces of freeze-thaw specimens (a) before, (b) plain concrete after, and (c) HyFRCafter freeze-thaw cycling (Ostertag and Blunt, 2008) . 12A specimen for the modified Slant Shear test consisting of one-half base concreteand one-half repair material (Momayez et al., 2005) . 14Consistency of a polyolefin FRC mix as it is discharged from the mixing truck(Dunn and Wolf, 2001) . 17Strux 90/40 fibers, manufactured by W.R. Grace . 35Fibermesh 650 fibers, manufactured by Propex. 35TUF-STRAND SF fibers, manufactured by The Euclid Chemical Company . 36FORTA-FERRO fibers, manufactured by Forta Corporation . 36Dramix 5D fibers, manufactured by Bekaert . 37Three types of Dramix steel fibers available from Bekaert. 381/2 cubic yard capacity concrete drum mixer . 42Distribution of fibers on the surface of the resting concrete, prior to the final fiveminutes of mixing . 43Rodding during a concrete slump test . 44Hand-held spud vibrator in use . 45Use of rubber mallet to obtain final consolidation efforts of the concrete . 46Moist cure room used to cure a majority of the testing specimens . 47Wet burlap placed over the top of the concrete specimens in the curing chamber . 47Plastic sheet placed over the top of the wet burlap to seal in the moisture . 48Measurement of the concrete slump, according to ASTM C143 . 49Air meter used to determine the concrete's air content, according to ASTM C231 . 50Determination of the fresh concrete unit weight, according to ASTM C138 . 518″ Extensometer used to measure the compressive strain of a concrete cylinder duringtesting, according to ASTM C39 . 52Compressive strength testing setup . 53Flexural performance (ASTM C1609) testing setup . 54Location of the LVDTs and the LVDT yoke for ASTM C1609 . 55Typical load-deflection curves for the average residual strength test(ASTM C1399, 2010) . 57Testing setup for the impact strength test, according to ACI Committee 544 . 58Top view of the impact strength testing setup. 58Failed impact specimen . 59Effect of fiber type on compressive strength . 65Effect of fiber type on modulus of elasticity . 66Experimental vs. theoretical modulus of elasticity values . 66FRC compressive strength cylinder at failure . 67Effect of fiber type on toughness . 68Effect of fiber type on equivalent flexural strength ratio . 68vii