Engineering tool for avoiding early cracking in concrete

Purpose and goal

The objective of the project was to gain knowledge on the influencing phenomena on plastic shrinkage cracking to establish a method with associated tools. The targeted goal was: 1.Grading crack causing factors early after casting 2.Document how and when the factors influence and how their impact could be reduced 3.Develop a tool for prognosis and follow up at building site 4.Establish recommendations on how the cracking could be avoided.

Expected results and effects

The work has resulted in a wide evaluation of the State of the Art regarding plastic shrinkage cracking. By testing the project has shown interesting effects when using various types of concretes and the work has shown convenient laboratory testing method to examine the cracking tendency. A methodology to avoid the cracking has been proposed and a prototype for follow up at building site can be used. Fully implemented this may imply that cracking could be reduced by 50 % with large economic benefit for the contractors and society 10 30 MSEK

Planned approach and implementation

Initially the work was performed as a literature study. Pilot tests were performed for control test-setup leading to major changes in testing methods. Then, tests were performed with variation of chosen parameters. At the same time models were programmed for evaporation implemented as a Smartphone application. Also, a unit was developed for documentation of parameters controlling evaporation. To work in parallel with basic research has been fruitful. Complexities in laboratory was underestimated -dealying project. Theoretical models were not fully covering the phenomomen.