Laboratory Evaluation of Abrasion Resistance of Latex-Modified Pervious Concrete

Transcription

1 Laboratory Evaluation of Abrasion Resistance of Latex-Modified Pervious Concrete Baoshan Huang, Ph.D., P.E., Associate Professor Hao Wu, Graduate Research Assistant Xiang Shu, Research Assistant Professor Qiao Dong, Graduate Research Assistant Dept. of Civil and Environmental Engineering The University of Tennessee, Knoxville Concrete Sustainability Conference 1 National Ready Mixed Concrete Association

2 Acknowledgment This study is financially supported by the Portland Cement Association (PCA) and the Georgia Department of Transportation (GDOT) Concrete Sustainability Conference 2 National Ready Mixed Concrete Association

3 Research Objectives To evaluate the abrasion resistance of latexmodified pervious concrete. To compare several laboratory abrasion test methods Concrete Sustainability Conference 3 National Ready Mixed Concrete Association

4 Materials Coarse Aggregates 100% 90% ASTM C 33 Gradation 80% 70% Limestone 60% No. 7 50% 40% No % Granite No. 7 No. 89 Single-sized limestone Percent Passing, % 20% 10% 9.5 mm (3/8 in.) ( mm) 4.75 mm (No.4) ( mm) 0% #7 Limestone #7 Granite #89 Limestone #89 Granite Sieve Size, mm Concrete Sustainability Conference 4 National Ready Mixed Concrete Association

5 Materials (Cont d) Latex was used to replace 10% cement. Natural sand to replace 7% coarse aggregate Fiber content = 09kg/m Concrete Sustainability Conference 5 National Ready Mixed Concrete Association

6 Base mix proportion Mix Design C:CA:W = 1:4.0:0.39 by weight Aggregate Size Group Cement (kg/m 3 ) Coarse Aggregate (kg/m 3 ) Water (kg/m 3 ) Natural Sand (kg/m 3 ) Latex (kg/m 3 ) Fiber (kg/ m 3 ) Control mm (9.5 to 12.5mm) 4.75mm (4.75 to 9.5mm) Fiber Latex Fiber + Latex Control Fiber Latex Fiber + Latex Concrete Sustainability Conference 6 National Ready Mixed Concrete Association

7 Mix Design Aggregate LS # 7 GR LS # 89 GR Mix Type Cement (typeⅠ) Latex Coarse Aggregate Natural Sand Water Fiber Control Latex modified Fiber added Latex & Fiber Control Latex modified Fiber added Latex & Fiber Control Latex modified Fiber added Latex & Fiber Control Latex modified Fiber added Latex & Fiber Concrete Sustainability Conference 7 National Ready Mixed Concrete Association

8 Pervious Concrete Samples Concrete Sustainability Conference 8 National Ready Mixed Concrete Association

9 Laboratory Performance Tests Physical Properties Air Void Content Water Permeability Mechanical Properties Compressive Strength Split Tensile Strength Abrasion Tests Cantabro Test APA Abrasion Test Surface Abrasion Test Concrete Sustainability Conference 9 National Ready Mixed Concrete Association

10 Physical Property Tests Air Content Test Water Permeability Test Concrete Sustainability Conference 10 National Ready Mixed Concrete Association

11 Mechanical Property Tests Compressive Strength Test Split Tensile Strength Test Concrete Sustainability Conference 11 National Ready Mixed Concrete Association

12 Abrasion Tests Cantabro Test APA Abrasion Test Surface Abrasion Test (After Kevern 2008) Concrete Sustainability Conference 12 National Ready Mixed Concrete Association

13 Cantabro Testing Conducted with steel ball charges Rotating speed: 30 cycles/min Total cycles: Concrete Sustainability Conference 13 National Ready Mixed Concrete Association

14 Cantabro Testing 150 mm 100 mm Before test After test Concrete Sustainability Conference 14 National Ready Mixed Concrete Association

15 APA Abrasion Test Vertical Load was increased to 5.5 kn for each wheel Concrete Sustainability Conference 15 National Ready Mixed Concrete Association

16 Studded APA Loading Wheels 120 mm 35 mm Concrete Sustainability Conference 16 National Ready Mixed Concrete Association

17 Specimens after APA Abrasion Test 125 mm 35 mm 300 mm Concrete Sustainability Conference 17 National Ready Mixed Concrete Association

18 Surface Abrasion Test (ASTM C 944) Load = 98 N Abraded area = cm 2 Diameter of abraded area = 8.25 cm 8.25 cm (After Kevern 2008) Concrete Sustainability Conference 18 National Ready Mixed Concrete Association

19 Effect Air Voids Results Effe ective Air Voids (%) #7Limestone# 7 #7Granite# 7 #89Limestone# #89Granite# Effe ective Air Voids (%) 35 # 7 Limestone # 7 Granite # 89 Limestone # 89 Granite Control Latex Fiber Latex & Fiber 0 Control Latex Fiber Latex & Fiber Top specimen Interior specimen Concrete Sustainability Conference 19 National Ready Mixed Concrete Association

20 Water Permeability Results Perm meability (mm/s) #7 Limestone #7 Granite #89 Limestone #89 Granite Perm meability (mm/s) #7 Limestone #7 Granite #89 Limestone #89 Granite Control Latex modified Fiber added Latex & Fiber 0 Control Latex modified Fiber added Latex & Fiber Top specimen Interior specimen Concrete Sustainability Conference 20 National Ready Mixed Concrete Association

21 Compressive Strength Results C ompressive e Strength, MPa #7 limestone #7 granite #89 limestone #89 granite Control Latex modified Fiber added Latex & Fiber Type Concrete Sustainability Conference 21 National Ready Mixed Concrete Association

22 Split Tensile Strength Results Strength, MP Pa Sp plit Tensile #7 limestone #7 granite #89 limestone #89 granite Control Latex modified Fiber added Latex & Fiber Type Concrete Sustainability Conference 22 National Ready Mixed Concrete Association

23 Cantabro Test Results a) Before test b) 50 cycles c) 100 cycles d) 150 cycles e) 200 cycles f) 250 cycles g) 300 cycles Concrete Sustainability Conference 23 National Ready Mixed Concrete Association

24 Weight Loss from Cantabro Test Aggregate LS # 7 GR LS # 89 GR Weight Loss (%) Mix Type Revolution Cycles Control Latex modified Fiber added Latex & Fiber Control Latex modified Fiber added Latex & Fiber Control Latex modified Fiber added Latex & Fiber Control Latex modified Fiber added Latex & Fiber Concrete Sustainability Conference 24 National Ready Mixed Concrete Association

25 Increase of Cantabro Loss with Cycles # 89 Limestone Mixture Weight Loss (% %) Control Latex Fiber Latex & Fiber Cycles Concrete Sustainability Conference 25 National Ready Mixed Concrete Association

26 Weight Loss Results after 300 Cycles Weigh ht loss, % #7 limestone #7 granite #89 limestone #89 granite Control Latex modified Fiber added Latex & Fiber Type Concrete Sustainability Conference 26 National Ready Mixed Concrete Association

27 APA Abrasion Results Weight lo oss, % #7 limestone #7 granite #89 limestone #89 granite 0.0 Control Latex modified Fiber added Latex & Fiber Type Depth of wear, mm #7 limestone #7 granite #89 limestone #89 granite 0.0 Control Latex modified Fiber added Latex & Fiber Type Concrete Sustainability Conference 27 National Ready Mixed Concrete Association

28 Correlation Analysis Effect of Air Voids Permeability, mm/s #7 Limestone #7 Granite #89 Limestone #89 Granite y = e x R² = Effective air voids, % Comp pressive strength, MPa y = e x R² = #7 limestone #7 granite #89 limestone #89 granite Effective air voids, % Permeability vs. Air voids Compressive strength vs. air voids Concrete Sustainability Conference 28 National Ready Mixed Concrete Association

29 Canta abro weight loss, % t loss, % APA weight Correlation Analysis Effect of compressive strength #7 limestone 5 y = x 70 y = x #7 granite #7 limestone R² = #7 granite 4 60 R² = #89 limestone #89 limestone 50 #89 granite 3 #89 granite Compressive strength, MPa Compressive strength, MPa Cantabro loss vs. compressive strength y = x R² = #7 limestone #7 granite #89 limestone #89 granite Compressive strength, MPa APA depth of wear, mm APA wear depth vs. compressive strength APA weight loss vs. compressive strength th Concrete Sustainability Conference 29 National Ready Mixed Concrete Association

30 Correlation Analysis Effect of Air Voids % Cantab bro weight loss, #7 limestone 7 #7 granite 6 #89 limestone y = e 0.054x 5 #89 granite R² = APA A weight loss, % 8 3 #7 limestone #7 granite #89 limestone #89 granite y = 1.259e x R² = Effective air voids, % Effective air voids, % 2 1 Cantabro loss vs. air voids APA weight loss vs. air voids Concrete Sustainability Conference 30 National Ready Mixed Concrete Association

31 Correlation Analysis btw Different Abrasion Tests Cantabro weight loss, % #7 limestone 80 #7 granite 70 #89 limestone y = e x 60 R² = #89 granite APA weight loss, % Concrete Sustainability Conference 31 National Ready Mixed Concrete Association

32 Comparison of Three Abrasion Tests Items Cantabro Test APA Abrasion Test Surface Abrasion Test Specimen Size Cylinder, 150-mm diameter by 100- mm height Beam, 300mm x 125mm x Beam, 300mm x 75mm 125mm x 75mm Test Equipment LA abrasion machine APA with studded wheels Test Period 10 min 1.5 h 6 min Weight Loss 35 to 80% (Lost weight: 1200 to 2800 g) 0.6 to 1.8% (lost weight: 33 to 101 g) Overall CV 10% 19% 32% Rotating-cutter Device 0.2 to 0.5% 11 to 28 g (lost weight: 11 to 28 g) Ratio of the lowest result to the result of the control mix 62% 45% 58% Concrete Sustainability Conference 32 National Ready Mixed Concrete Association

33 Conclusions and Summary APA Abrasion Best sensitivity i i and sufficient i repeatability Studded steel wheels and high load increased the severity of abrasion. Surface Abrasion Unable to differentiate between all the mixtures. Unfavorably low weight loss values Longer test period and/or bigger abraded area recommended Concrete Sustainability Conference 33 National Ready Mixed Concrete Association

34 Conclusions and Summary Cantabro Test Fairly good sensitivity and repeatability High weight loss values Not so effective in evaluating of the abrasion resistance Failure due to impact rather than abrasion Improve Abrasion Resistance of PCPC Use small size aggregate Add latex Concrete Sustainability Conference 34 National Ready Mixed Concrete Association

35 THANK YOU! Concrete Sustainability Conference 35 National Ready Mixed Concrete Association