Low slump overlays are an important method to extend the life of bridge decks. The concrete mixture for low slump overlays has not changed in the last 30 years and these overlays show extensive cracking within a few years of placement. The objective of this research project is to minimize the cracking in low slump concrete overlays for mixtures placed with a volumetric mixer. These mixtures need to obtain a low permeability in the NT Build 492 and achieve a 28-day compressive strength of 4000 psi. The objectives of the research include:
i. Examining the most promising mixtures and documenting their performance
ii. Determining the impact of glass fibers to reduce cracking but still provide constructible concrete
iii. Implementing a mixture with and without fibers on separate field projects and documenting the construction and performance of low slump overlays
This work has already been implemented on six field projects, and based on talks with MnDOT engineers, these projects have been deemed a success for having a low amount of cracking while meeting specifications. Also, the contractors who have used these mixtures have requested to use them on other projects. This shows the success of the work.

Infrastructure Assets: Bridge, Highway Assets
Resource Types: Research Report
Capabilities: Tools & Technology
Management Processes: Performance Based Planning & Programming