Chapter 8: Micro-Surfacing

Troubleshooting

This section provides information to assist the maintenance personnel in troubleshooting problems with micro-surfacing, along with “dos and don’ts” that address common problems that may be encountered during the course of a project. The troubleshooting guide presented in Table 6 associates common problems with their potential causes. For example, an unstable emulsion, too little water in the mix, incompatibility between the emulsion and the aggregate, and so on, may cause a slurry surface to delaminate.

Table 6: Trouble Shooting Micro-Surfacing Job Problems
Cause	brown	Whitish	Failure to Set	Poor Coating	Delayed Opening to Traffic	Breaks in Box	Ravels	Flushes	Delamination	Segregation
Cause	Problem
Emulsion
Emulsion Unstable	No	No	No	• Yes	No	• Yes	No	No	• Yes	No
Emulsion too Stable	• Yes	No	• Yes	No	• Yes	No	• Yes	No	No	No
Emulsion too hot	No	No	No	No	No	• Yes	No	No	No	No
Too Little Emulsion	• Yes	No	No	• Yes	No	No	• Yes	No	No	No
Too Much Emulsion	No	No	No	No	No	No	No	• Yes	No	No
Mix
Mix: Too many fines	No	No	No	• Yes	No	• Yes	• Yes	No	No	No
Mix: Too much cement	No	• Yes	No	No	No	• Yes	No	No	No	No
Mix: Too little cement	No	No	• Yes	No	• Yes	No	• Yes	No	No	• Yes
Mix: Too little additive	No	No	No	• Yes	No	• Yes	• Yes	No	No	No
Mix: Too much additive	No	• Yes	• Yes	No	• Yes	No	• Yes	No	No	No
Mix: Too much water	• Yes	No	• Yes	No	• Yes	No	• Yes	• Yes	No	• Yes
Mix: Too little water	No	• Yes	No	• Yes	No	• Yes	• Yes	No	• Yes	No
Mix: Aggregate/emulsion not compatible	No	No	• Yes	• Yes	• Yes	No	• Yes	No	• Yes	• Yes
Conditions
Condition: Too hot	• Yes	No	No	• Yes	No	• Yes	• Yes	• Yes	No	No
Condition: Too cold	No	No	• Yes	No	• Yes	No	• Yes	No	• Yes	No
Condition: Rain	• Yes	No	• Yes	• Yes	• Yes	No	• Yes	• Yes	• Yes	No
Condition: High humidity	No	• Yes	• Yes	No	No	No	No	No	No	No
Surface
Surface: Fatty	No	No	• Yes	No	No	No	No	• Yes	No	No

In addition to the troubleshooting guide, Table 7 lists some commonly encountered problems and their recommended solutions.

Table 7: Common Problems and Related Solutions
Problem	Solution
Uneven Surface – Wash Boarding	Ensure the spreader box is correctly set up. Ensure the viscosity of the mix is not too high. Make adjustments so that the mix does not break too fast. Wait until the ambient temperature is lower. Use water sprays on the front of the spreader.
Poor Joints	Reduce the amount of water at start up. Use water spray if runners of spreader box are running on fresh material.
Excessive Ravel	Add cement and reduce additive so that the mix breaks and cures faster. Check aggregate to ensure the clay fines are not too high. Control traffic longer and at low speeds. Wait until fully cured before allowing traffic. Wait until mix is properly set before brooming or opening to traffic.