Concrete pump day is exciting; however, mistakes on pump day could be costly. ZEGO Building Systems has compiled a 5-step guide to ensure that your concrete pump goes smoothly.
5-step guide to ZEGO pump day
1: The 5 Ps: Prior Planning Prevents Poor Performance
Check that all blocks have been laid in a stretcher bond pattern.
Check that all walls, especially corners and openings are braced adequately.
Check that any cut blocks have been sealed with recommended polyurethane expandable foam.
Check correct placement of vertical and horizontal reinforcement has been done correctly inside the walls.
Check crew have appropriate safety gear including gloves.
2: Check the slump before you pump
The proper ratios of a concrete mix will determine its strength, pressure and workability and this is best done with a ‘slump’ test. The concrete strength will be nominated by your project engineer; however, 32mpa, 180mm slump with a 10mm aggregate using a 50mm block fill hose is recommended to ensure a smooth mix that pours nicely around the reinforcement to prevent voids.
Concrete that is wet (high slump) will settle more and have a greater distance between the reo and the concrete.
It is recommended to test concrete slump before pouring from each new concrete truck.
3: Stick to the plan
Pick a starting location and pour in a continual direction around the building.
Let the concrete flow naturally and push at a 45-degree angle so the concrete flows smoothly in the direction you are moving.
Do not pour any higher than 3 courses of blocks (i.e., 900 high maximum) per hour as per the Concrete code. The pressure of the ICF form is based on how high the wet concrete is poured at once (900 maximum/hour).
By pouring in courses, the first pour of concrete starts to solidify, which reduces the pressure on the lower forms by the second course.
When pouring around windows and corners, pour a small amount on either side of the openings to prevent too much concrete building up on one side.
Don’t risk concrete pressure build-up; although the forms are strong and block failure is rare, don’t take the risk. Slow and steady wins the race.
4: Team Work = Dream Work
You’ve got your pump booked and everything ready to go; however, no matter how organised and well planned you are, you must make sure that the crew know their jobs on the day and are prepared.
Some jobs to designate include:
Person to test concrete slump and communicate with the truck drivers;
Person pouring the concrete and communicating with the pump operator;
1-2 crew members checking openings and height of concrete in the walls during the pour;
Crew member levelling the concrete and adjusting the bracing;
Crew member continuously cleaning up around the site during and after the pour.
5: Last but not least reminders
Communication is paramount on concrete pour day. Set the goal for the day and communicate with the crew regularly, especially any challenges or responsibilities they have been designated.
Start the pour as early as possible in the day. Do not start a concrete pour after 9am on large projects (7am is optimum). This will ensure your crew are fresh and relaxed and the concrete pump operator does not rush you.
If for some reason, the concrete is not the right slump or is starting to go off in the hopper, please send the truck back and delay your concrete pour until a fresh batch arrives. The concrete must pour freely and easily.