Spelling suggestions: "subject:"freezethaw tests"" "subject:"freethaw tests""
1 |
Evaluation of Canadian unconfined aggregate freeze-thaw tests for identifying nondurable aggregates.Mummaneni, Santosh Kumar January 1900 (has links)
Master of Science / Department of Civil Engineering / Kyle Riding / Concrete is most widely used material in construction industry, which is made up of cement, water and aggregates as its major ingredients. Aggregates contribute to 60 to 75 % of the total volume of concrete. The aggregates play a key role in the concrete durability. The U.S Midwest has many aggregates that can show distress in the field under freezing and thawing conditions. The objective of this research was to determine if the Test Method for the Resistance of Unconfined Coarse Aggregate to Freezing and Thawing, method CSA A23.2-24A, could be used to differentiate good from poor performing aggregates in concrete. In this study fifty one KDOT aggregates (including twelve ledge and thirty nine production samples) were tested for freeze thaw resistance using CSA A23.2-24A test method and were compared to the results of the standard KDOT aggregate qualification tests. In addition to performing the CSA test method using a 3% sodium chloride solution, a subset of the aggregates were tested using either a 3% magnesium chloride or calcium chloride solution to determine the effects of the salt type on the aggregate performance. No correlation was found between the CSA A23.2-24A test method results and the standard KDOT aggregate qualification tests. The results also indicated that the mass loss in the CSA A23.2-24A was similar for the aggregate sizes tested. The use of alternate salt solutions like MgCl2 and CaCl2 resulted in increased freeze thaw mass loss in limestone aggregates.
|
2 |
Freeze-Thaw Effects on Soils Treated for Water RepellencyFink, Dwayne H., Mitchell, Stanley T. 12 April 1975 (has links)
From the Proceedings of the 1975 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 11-12, 1975, Tempe, Arizona / Water can be supplied to many arid areas by harvesting the precipitation that falls on artificially prepared water-repellent soil catchments. The failure, in 1973, of wax-treated water harvesting catchment led to this study which indicates that the failure was due to swelling and shrinking of the treated soil which caused complete structural breakdown and loss of repellency. The laboratory freeze-thaw studies demonstrated that the smoother the plot, the less chance of freeze-thaw damage. Generally, coarser-textured soil can withstand freeze-thaw cycles better than finer-textured soils. Soil properties, other than texture, may also affect resistance to damage by freeze-thaw cycles. Increasing the repellent application rate may improve resistance to breakdown.
|
Page generated in 0.0313 seconds