Date of Award

8-2010

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Civil Engineering

Advisor

Rangaraju, Prasad R

Committee Member

Rangaraju , Prasad R

Committee Member

Putman , Brad J

Committee Member

Klotz , Leidy E

Abstract

Highways form the backbone of transportation in United States. As a result, issues related to distress in pavements and use of chemicals on pavement forms one of the major focus areas of highway agencies. One of the forms of distress in concrete pavements is Alkali silica reaction (ASR). External source of alkalis in the form of deicing chemicals play a key role in accelerating ASR. Sodium chloride or Rock salt is one of the oldest forms of deicers. Several research studies have been done on ASR under the influence of sodium chloride and calcium chloride. Limited information is available on alkali silica effect due to potassium chloride and magnesium chloride. This research discusses laboratory evaluations to assess effect of chloride deicers on alkali silica reactivity. Variations in exposure conditions, cement and aggregate are introduced to understand the effect in a wider spectrum. Tests include use of fused silica as reactive aggregate and Type I Cement. Tests are carried out at two temperature conditions, 38¡C and 80¡C.
Tests show that sodium chloride and potassium chloride solutions cause more expansion in mortar specimens than sodium hydroxide solution. Calcium chloride and magnesium chloride have no effect on ASR. ASR was accelerated at higher temperature. Type of cement does not have a major influence on alkali silica reactivity in the presence of external deicing solutions. Formation of chloroaluminates or Friedel's salt can accelerate the expansive reaction. However, the expansive effect was associated with alkalis only.

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