Need a Concrete Engineer

[Doc Holiday]

It rained 2 hours after builder poured slab for my to be home, we bitch about it to regional manager and my builder agreed to pay for someone to test it. I have no idea who does it... Any ideas?

how much did it rain, big rain? little rain? rain would normal only mess up the finish of the concrete, what is the slab for? drive way back porch or a footer?

[Vampire the buffet slayer]

Is the concrete the foundation of the home?

Im assuming it is , if that is the case did you have a geo tech come out and Test the soil on which was poured?

Why Im say this is the flaking might not be your only problem. If the structural soundness of the concrete was comprimised, the settling of the of the concrete can cause cracks.

[Floppin]

Is the concrete the foundation of the home?

Im assuming it is , if that is the case did you have a geo tech come out and Test the soil on which was poured?

Why Im say this is the flaking might not be your only problem. If the structural soundness of the concrete was comprimised, the settling of the of the concrete can cause cracks.

I don't know how his city/county does their inspections and coding, but in every place that I've ever built you have to have your footer holes and foundation trenches inspected. They test the soil for all kinds of poo. I had to dig down 40 feet and back-fill with gravel and layers of landscape fabric for this one house that was being built, unbeknownst to us before hand, on a spring field.

[Vampire the buffet slayer]

Yeah, I work in Raleigh, and here its kinda the inspectors decision wether or not to have a geotech come out or not.

Idk if his local is the same or not.

Ive had them tell me its fine when i would bury a probe to the handle, turn around a month later and have us under cutting stuff that couldve been considered processed fill.

unbelieveable.

[Ja Rhule]

I'm in Mint Hill, NC. Geotech dude was supposed to come out either today or tomorrow. I should know the answer soon. I'll let ya'll know.

[charlotte49er]

They pour concrete right through water for bridge structures.

If he covered the concrete with plastic it should be alright. Concrete is thermogenic. Meaning it creates heat as it cures, and continues to cure thoughout it's lifetime. The biggest worry with concrete is that you keep it from freezing. (Screws up the thermogenic process and will weaken the concrete.)

Also is something you can pour sloppy wet or with very little water. (Why to do think Quickrete says to dig hole, fill with Quickrete, then pour water on it? In fact, for around a pool, many pool builders will pour the concrete, tamp in decrative stone and wash off the top exposing the stone.

If you have rebar and screen in it, I don't think you have any worries.

However, heat and humidity can cause the concrete to cure TOO fst and cause cracks. For that reason, Concrete poured during hot and humid times should be hosed down to prevent this!

And if you don't think that my years in construction paid off, this from Wikipedia:

Curing

In all but the least critical applications, care needs to be taken to properly cure concrete, to achieve best strength and hardness. This happens after the concrete has been placed. Cement requires a moist, controlled environment to gain strength and harden fully. The cement paste hardens over time, initially setting and becoming rigid though very weak and gaining in strength in the weeks following. In around 4 weeks, typically over 90% of the final strength is reached, though strengthening may continue for decades.^[22]

The conversion of calcium hydroxide in the concrete into calcium carbonate from absorption of CO₂ over several decades further strengthen the concrete and making it more resilient to damage. However, this reaction, called carbonation, lowers the pH of the cement pore solution and can cause the reinforcement bars to corrode.

Hydration and hardening of concrete during the first three days is critical. Abnormally fast drying and shrinkage due to factors such as evaporation from wind during placement may lead to increased tensile stresses at a time when it has not yet gained sufficient strength, resulting in greater shrinkage cracking. The early strength of the concrete can be increased if it is kept damp during the curing process. Minimizing stress prior to curing minimizes cracking. High-early-strength concrete is designed to hydrate faster, often by increased use of cement that increases shrinkage and cracking. Strength of concrete changes (increases) up to three years. It depends on cross-section dimension of elements and conditions of structure exploitation.^[23]

During this period concrete needs to be kept under controlled temperature and humid atmosphere. In practice, this is achieved by spraying or ponding the concrete surface with water, thereby protecting the concrete mass from ill effects of ambient conditions. The pictures to the right show two of many ways to achieve this, ponding – submerging setting concrete in water and wrapping in plastic to contain the water in the mix. Additional common curing methods include wet burlap and/or plastic sheeting covering the fresh concrete, or by spraying on a water-impermeable temporary curing membrane

.

Properly curing concrete leads to increased strength and lower permeability and avoids cracking where the surface dries out prematurely. Care must also be taken to avoid freezing, or overheating due to the exothermic setting of cement. Improper curing can cause scaling, reduced strength, poor abrasion resistance and cracking.