In brief
- A low concrete transport bid usually means the haul, standby or slump-loss cost sits outside the price and returns as a variation.
- Ask for the bidder's mixer count, cycle times, batching point and slump test record before comparing transport rates.
- Segregation and cold joints appear when transport time runs past what the mix was designed to tolerate, so confirm the allowance against the engineer's specification.
Contents
Concrete transport underbidding risks in Borama come from the same gap: the tender price covers drums and fuel, then leaves out waiting time, drum revolutions, water for washout and the extra trips a short pour window demands. On a hot, dry inland site those items decide whether the concrete arrives workable or arrives separated. The client pays the difference later, usually at placement.
What does a low transport rate leave out?
A rate built only on distance and diesel misses the fixed costs of the day. A mixer truck charges for the hours it is on site, whether or not it is discharging, and a pump or chute crew stands idle while it waits. Add washout water, a standby drum, and a second trip if the first load queues behind formwork. Ask each bidder to list the number of mixers, the batching point, the drum revolutions per minute on the road, and the site waiting allowance in writing. Compare those lists side by side rather than the bottom line. If the bidder cannot say where the concrete is batched or how long the haul takes, the estimate is a guess, not an allowance. Confirm any cycle-time or slump limit against the project's specification and the engineer before accepting the transport plan.
What happens to the concrete before placement?
Segregation before placement is the visible symptom of a transport plan that was priced too tightly. Long haul, high drum speed, hot air and a mix that was batched wet to keep it flowing all push aggregate and paste apart. Workers then add water at the chute to make it placeable, which raises the water-cement ratio and drops strength. Watch the first discharge from each truck: if mortar runs ahead of the coarse aggregate, the load has separated. A slump test at the point of placement, not at the plant, is the record that shows it. General practice keeps haul and discharge inside the time the mix was designed for, and drum revolutions within the range on the delivery ticket, but the project specification and the engineer set the figure that applies. Where the record is thin, the repair cost lands on the client.
How do you test the transport assumption before award?
Test it before you sign, not after the first pour. Ask for a transport method statement that names the batching point, the route, the number of mixers, the pour rate they can sustain and the contingency if one mixer breaks down. Walk a recent site the bidder supplied and ask the supervisor what the actual waiting time was. Request slump and cube test records for a comparable pour. Check the contract for what it allows on standing time, extra trips and washout disposal, and ask the engineer whether a delivery ticket and slump record are required for every load. For the local picture, ask the municipal engineer's office directly what records it keeps on past pours and route access so you can check the assumption yourself.
What to do next
Send every bidder the same transport questionnaire: batching point, mixer count, cycle time, pour rate, standby terms and slump test procedure. Ask for the completed forms and one recent delivery record before you compare prices. Then sit with the engineer, read the specification clause on haul time, and confirm the transport allowance matches it.
Frequently asked questions
Is a low concrete transport bid always a problem in Borama?
Not always. A bidder with a short haul and a spare mixer can price lower honestly. The check is whether the bid lists mixer count, cycle time, standby and slump control, and whether a recent delivery record backs it up.
How do I check segregation before placement?
Watch the first discharge from each truck for mortar running ahead of the aggregate, and take a slump test at the point of placement. Confirm the allowable haul time and drum revolutions against the project specification and the engineer.
Local reporting: this article is written for building work in Borama and Somaliland. Ground conditions, prices and rules differ between places; confirm the details for your own site.