A Study of Portland Cement Maintenance Mix and Set Accelerators, R-249, 1970

(1970) A Study of Portland Cement Maintenance Mix and Set Accelerators, R-249, 1970. Transportation, Department of

pdf
Preview
PDF
IADOT_r249_Study_Portland_Cement_Maintenance_Mix_Set_Accelerators_1970.pdf

File Size:177kB

Abstract

The large volume of traffic on the interstate system makes it difficult to make pavement repairs. The maintenance crew needs 4-5 hours to break out the concrete to be replaced and prepare the hole for placing new concrete. Because of this it is usually noon before the patch can be placed. Since it is desirable to remove the barricades before dark there are only 7-8 hours for the concrete to reach the required strength. There exists a need for a concrete that can reach the necessary strength (modulus of rupture = 500 psi) in 7-8 hours. The purpose of this study is to determine if type III cement and/or an accelerator can be used in an M-4 mix to yield a fast setting patch with very little shrinkage. It is recognized that calcium chloride is a corrosive material and may therefore have detrimental effects upon the reinforcing steel. The study of these effects, however, is beyond the scope of this investigation.

Item Type: Departmental Report
Keywords: Accelerating agents, Calcium chloride, Concrete construction, Concrete placing, Interstate highways, Maintenance
Subjects: Transportation > Pavements
Transportation > Pavements > Concrete
Transportation
Transportation > Materials
Transportation > Roads and highways
Transportation > Maintenance and preservation
ID Code: 17215
Deposited By: Iowa DOT Library
Deposited On: 13 Jun 2014 12:10
Last Modified: 22 Jan 2015 19:55
URI: http://publications.iowa.gov/id/eprint/17215