Methods to Increase Durability of Reactive ("D" Cracking) Coarse Aggregate in Portland Cement Concrete, MLR-73-01, 1973

(1973) Methods to Increase Durability of Reactive ("D" Cracking) Coarse Aggregate in Portland Cement Concrete, MLR-73-01, 1973. Transportation, Department of

[img]
Preview
PDF
ISHC_MLR_73_01_Methods_Increase_Durability_Reactive_D_Cracking_Course_Aggregate_PCC_1973.pdf

File Size:256kB

Abstract

The coarse aggregates used for Portland Cement concrete in southwest Iowa have exhibited a poor serviceability. This early failure is attributed to a characteristic commonly referred as "D" cracking. "D" line cracking is a discolored area of concrete caused by many fine, parallel hairline cracks. "D" line cracking is primarily caused by the movement of water in and through coarse aggregate with a unique pore structure. The presence of the water in the aggregates at the time of freezing causes the "D" cracking to occur and early failure. By making the pore structure less permeable to moisture, it is thought the durability factor of the concrete should increase. By drying the aggregate before mixing and then mixing with the cement, the particles of cement should enter the outer pore structure, and upon hydration make the pore structure less permeable to moisture.

Item Type: Departmental Report
Keywords: Aggregates, Cement, Concrete, Concrete pavements, D cracking, Durability, Freeze thaw durability, Limestone aggregates, Moisture content, Portland cement concrete, R-259, MLR-73-01
Subjects: Transportation
Transportation > Materials
Transportation > Materials > Gravel and aggregates
Transportation > Roads and highways
ID Code: 21469
Deposited By: Leighton Christiansen
Deposited On: 01 Feb 2016 20:10
Last Modified: 01 Feb 2016 20:10
URI: http://publications.iowa.gov/id/eprint/21469