In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Become an ACI Member
Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
American Concrete Institute
38800 Country Club Dr.
Farmington Hills, MI
Feedback via Email
Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Title: Surface Strain Experienced by Mortar in Wetting-Drying Cycles and Deicer Salt Application
Author(s): Peter P. Hudec and Martin Ondrasik
Publication: Special Publication
Appears on pages(s): 853-878
Keywords: Deicing; drying; expansion; mortars (materials); osmotic forces; sands;
shales; water-cement ratio; welting.
Abstract:The scaling of concrete and mortar involves sub-parallel de-laminations of material from the surface. To produce this phenomenon, differential stresses parallel to the surface and resulting in differential strain must be active. This research measured the differential strain developed along the surface of specially shaped mortar bars upon their wetting, drying, and osmosis due to application of deicer salts. Mortar bars were made at a w-c ratio of 0.4 and 0.6 with shaley sand and high quality dolomite as aggregate. The sand is known to cause surface scaling. The bars were cast in a ‘half circle’ shape. The normally cured samples were dried, and all but the outer surface of the ‘half circle’ were sealed.. This allowed the ingress of water and solutions from one direction only, such as would occur in an ‘infinite’ concrete surface. Steel pins were secured to the ends of the half circle to facilitate measurement of the strain. The strain of the specimens was measured during the following states: 1. dry samples, 2. saturating in water, 3. drying, 4. saturated, placed in saline solutions, 5. then placed in pure water. The results show that as the water entered or left the surface, stresses developed which were sufficient to deform the ends of the half circle up to 0.6% of the diameter distance. Largest deformations took place upon wetting, followed by those on drying, and the least deformation resulted from osmotic forces. When the samples had equilibrated, i.e., became either fully saturated, dried, or the pore fluid composition equaled that of the saturating medium, the strain was relaxed. Water-cement ratio influenced the time of maximum strain development and aggregate and cement type determined the magnitude of the strain.
Click here to become an online Journal subscriber