UVM Theses and Dissertations
Format:
Print
Author:
Suozzo, Mark Joseph
Dept./Program:
Civil and Environmental Engineering
Year:
2012
Degree:
M.S.
Abstract:
This study evaluates the factors affecting the testing of strength and hydraulic parameters of pervious concrete pavement (PCP), presents results of long-term infiltration monitoring and cleaning operations, and investigates the effects of fly ash on PCP. The specific objectives of this study were to: (1) determine how rubber capping and sulfur capping affect compressive strength measurements of PCP; (2) determine the effect of height to diameter (H:D) ratio of cylindrical specimens on compressive strength measurements of PCP; (3) compare various methods used to determine infiltration rate of PCP in the field to one another and to laboratory measurements of hydraulic conductivity; (3) monitor two PCP facilities in Vermont for changes to infiltration rate over time (4) evaluate the effects of various cleaning methods on the restoration of infiltration rates; and (5) ascertain the compressive strength and hydraulic conductivity of PCP incorporating fly ash at low water to cement ratios.
Various mix designs were used to create cylindrical specimens with H:D ratios of 2:1, 1.5:1 and 1:1; both rubber and sulfur capping methods were applied to a set 2:1 and 1.5:1 H:D specimens. Two field sites and laboratory slab specimens were tested with various infiltration methods including, single ring infiltrometer, double ring infiltrometer, and a falling head infiltrometer, which was developed at The University of Vermont. Cylindrical specimens were cored from slabs at locations of infiltration testing and tested for hydraulic conductivity. Two field facilities were selected and infiltration rates were measured at several sites over a year long period. Street sweeping, vacuum truck cleaning, pressure washing, hand vacuuming, and a combination of hand vacuuming and pressure washing were evaluated at the field facilities to determine increases to infiltration rate. Mix designs, based on the field facilities, incorporating 0%, 5%, 10%, and 20% fly ash were cast and tested for compressive strength and hydraulic conductivity.
Capping with rubber pads was found to provide more consistent compressive strength measurements compared to sulfur capping for both H:D ratios studied. H:D ratios less than the standard 2: 1 were found to increase results of compressive strength measurements; however, a ratio of 1:1 was found to provide inconsistent results. Compressive strength specimens with H:D ratios less than 2: 1 can be divided by 1.1 to estimate compressive strength of 2:1 H:D specimens. Results of laboratory hydraulic conductivity, single ring, double ring and falling head infiltrometer testing were found to correlate linearly to one another with a relation of 1.0 : 1.8 : 1.5 : 9.0 for 6" thick PCP. Long-term field monitoring of infiltration rates indicated reductions of 59% and 26% for the facilities investigated. Cleaning methods were found to differ in effectiveness, with average restoration rates of 21% for street sweeping, 30% for vacuum truck cleaning, 85% for pressure washing, 10% for hand vacuuming, and 100% for combined pressure washing and vacuuming. Addition of fly ash was found to slightly increase unit weight and compressive strength of PCP without reducing hydraulic conductivity. PCP incorporating fly ash resulted in mix designs with water to cement ratios of 0.25 without reduced strength that is typical of PCP in this range.
Various mix designs were used to create cylindrical specimens with H:D ratios of 2:1, 1.5:1 and 1:1; both rubber and sulfur capping methods were applied to a set 2:1 and 1.5:1 H:D specimens. Two field sites and laboratory slab specimens were tested with various infiltration methods including, single ring infiltrometer, double ring infiltrometer, and a falling head infiltrometer, which was developed at The University of Vermont. Cylindrical specimens were cored from slabs at locations of infiltration testing and tested for hydraulic conductivity. Two field facilities were selected and infiltration rates were measured at several sites over a year long period. Street sweeping, vacuum truck cleaning, pressure washing, hand vacuuming, and a combination of hand vacuuming and pressure washing were evaluated at the field facilities to determine increases to infiltration rate. Mix designs, based on the field facilities, incorporating 0%, 5%, 10%, and 20% fly ash were cast and tested for compressive strength and hydraulic conductivity.
Capping with rubber pads was found to provide more consistent compressive strength measurements compared to sulfur capping for both H:D ratios studied. H:D ratios less than the standard 2: 1 were found to increase results of compressive strength measurements; however, a ratio of 1:1 was found to provide inconsistent results. Compressive strength specimens with H:D ratios less than 2: 1 can be divided by 1.1 to estimate compressive strength of 2:1 H:D specimens. Results of laboratory hydraulic conductivity, single ring, double ring and falling head infiltrometer testing were found to correlate linearly to one another with a relation of 1.0 : 1.8 : 1.5 : 9.0 for 6" thick PCP. Long-term field monitoring of infiltration rates indicated reductions of 59% and 26% for the facilities investigated. Cleaning methods were found to differ in effectiveness, with average restoration rates of 21% for street sweeping, 30% for vacuum truck cleaning, 85% for pressure washing, 10% for hand vacuuming, and 100% for combined pressure washing and vacuuming. Addition of fly ash was found to slightly increase unit weight and compressive strength of PCP without reducing hydraulic conductivity. PCP incorporating fly ash resulted in mix designs with water to cement ratios of 0.25 without reduced strength that is typical of PCP in this range.