Concrete Conveyors – Troubleshooting to Keep Things Flowing Smoothly

Concrete conveyors are a common sight at new housing developments. In fact, it’s hard to imagine a new house being built without one. But even the highly efficient concrete conveyor can get bogged down. An article published by The Aberdeen Group talks about fine tuning your concrete conveyor to maximize efficiency.

Conveying Concrete - Common Problems and Solutions

The most common issues with concrete conveyors are summarized in the Aberdeen article. These include:

• Spillage. If concrete spills off the edge of the belt, chances are the conveyor belt was overloaded. Do not let the charging hopper get filled up, as it is designed to absorb surges in flow. If the belt tension on the conveyor is too low, it can also cause spilling. Use the conveyor’s pulleys to adjust the tension.

• Discharge hopper contains concrete plugs. This could be caused by overloading the belt. If the discharge hopper is tilted too far, it may prevent gravity from pulling the concrete through the hopper. Foreign objects in the aggregate or broken bits of dry concrete may also cause obstructions in the discharge hopper.

• Aggregate rollback. High concrete slump or inconsistent loading can cause rollback. If you are using the conveyor at a steep angle, be sure to pay close attention to maximum slump and the amount being loaded on the belt. When possible, make sure concrete flows down the chute in the direction the belt is traveling.

• Segregation after discharge. If segregation occurs after the concrete leaves the belt, the discharge hopper may not be the right design for the job. The Aberdeen article recommends installing a tremie hose at least 2 feet long at the discharge site, and then adding discharge chutes. You should always check manufacturer guidelines to ensure the conveyor can handle the extra load.

• Dry concrete on the belt. If the belt is stopped because of job delays, it is best to empty the belt to avoid drying. If there more than a couple of minutes passes between the time you empty the belt and the time you add fresh concrete, you should stop the belt and disengage the belt wiper to reduce wear and tear. Alternatively, you could wet the belt.

• Mortar carryback. Carryback reduces the slump and workability of the concrete. This problem usually stems from worn-out or misadjusted belt wipers.

Keeping Your Concrete Conveyor Clean

Cleanliness is the key to efficient operation of your conveyor. An article in the trade journal of the National Precast Concrete Association offers these tips for maintaining a clean concrete conveyor:

•Wipers direct the mortar for proper discharge. It is critical that they be kept clean. Follow manufacturer guidelines for cleaning and do it regularly. As the article says, many people neglect the wipers until it is too late and a problem occurs.

•Always lock out your concrete conveyor before cleaning, and disconnect it from its power source. To clean, water washing of belts is not recommended. Instead, tap it lightly, wire brush it and oil it. The manufacturer might also have a cleaning procedure that you can follow.

Clean and Trouble-Free Concrete Conveyors

Learning how to troubleshoot and maintain your concrete conveyor will ensure it functions at optimum levels for a long time to come. The advice provided here is just a starting point. For detailed information, consult the manufacturer.