Quality control is mandatory for making and maintaining good quality concrete. At Garrott Brothers we realize the importance of Quality Control and do our part to enforce Quality Control. Our Quality control team is ACI and DOT certified with years of experience in the concrete industry, and NRMCA Certified in TN and KY. For any questions regarding Quality Control of your concrete project please contact us.
Cold Weather presents many problems for the concrete industry. The most common problem is with having the concrete freeze and/or go through freeze thaw cycles before acquiring adequate strength. This and other problems can be avoided with precautionary steps. Protecting exposed concrete in these conditions can prevent costly issues down the road..
1. Use air-entrained concrete when exposure to moisture and freezing and thawing conditions are expected.
2. Keep surfaces in contact with concrete free of ice and snow and at a temperature above freezing prior to placement.
3. Place and maintain concrete at the recommended temperature.
4. Place concrete at the lowest practical slump.
5. Protect plastic concrete from freezing or drying.
6. Protect concrete from early-age freezing and thawing cycles until it has attained adequate strength.
7. Limit rapid temperature changes when protective measures are removed.
Hot weather problems are most frequently encountered in the summer, but the associated climatic factors of high winds and dry air can occur at any time, especially in arid or dry climates.
High temperatures alone cause increased water demand, which in turn will raise the water-cement ratio and yield lower potential strength. Higher temperatures tend to accelerate loss of slump and entrained air. Hot weather conditions can produce a rapid rate of moisture evaporation from the surface as well as the accelerated setting time, among other problems. Concrete that is cure at high temperatures early will not be as strong at 28 days as the same concrete cured at more moderate temperatures (70°F). Generally, high relative humidity tends to reduce the effects of high temperature.
High temperatures, high wind velocity, and low relative humidity can affect fresh concrete in two ways: the high rate of evaporation may induce early plastic shrinkage or drying shrinkage crackage, and the evaporation rate can remove surface water necessary for hydration unless proper curing methods are employed. Thermal cracking may result from rapid drops in the temperatures of the concrete, such as when slabs or walls are placed on a hot day followed by a cool night. High temperature also accelerates cement hydration and contributes to potential cracking in massive concrete structures.
The keys to successful hot weather concreting are: (1) recognition of the factors that affect concrete and (2) advanced planning to minimize their effects. Use proven recommendations for adjusting concrete proportions, such as use of water reducing admixtures. Perhaps a moderate heat of hydration cement (ASTM Type II-moderate heat), pozzolanic admixture (fly ash) or ground granulated furnace blasted slag can reduce the effects of high temperatures.
Advance timing and scheduling to avoid delays in delivery, placing, and finishing is a must: trucks should be able to discharge immediately and adequate personnel should be available to place and handle the concrete. When possible, deliveries should be scheduled to avoid the hottest part of the day. In case of extreme temperature conditions or with mass concrete, the concrete temperature can be lowered by using chilled water or ice as part of the mixing water. Other measures, such as sprinkling and shading the aggregate can be used to help lower the temperature of the concrete. If low humidity and high winds are predicted, then windbreaks, surface evaporator retarder, sunscreens, or mist fogging may be needed to avoid plastic shrinkage cracking in slabs.
Download this informative pdf to find out what plastic shrinkage cracking is and how to prevent it.
DOWNLOADFirst measure the length, width and depth of all the areas where you are pouring concrete. You can give this information to your Customer Service Representative when you place your order or you can use our concrete calculator.
Take a look at our plant locations link at the top of the page. Once you have found the location most convenient to your job site contact our customer service representative who will gladly assist you in scheduling a delivery.
View Plant LocationsIf you have placed an order with us and the weather forces you to pour on a later date, contact us as soon as you can. We will put a hold on your order and work with you to reschedule it.
Slump refers to how wet or dry fresh concrete is upon delivery. Slump is based on a 12-inch scale. The lower the slump number, the drier the concrete will be. A slump of 1 is very dry concrete, while a slump of 12 will run like water. This is a key piece of information that we will need to mix your concrete batch. If you are unsure of what slump you need our Customer Service Representative can help you make the best slump option based upon your project.
Yes, if you place your order for these products when you make your concrete order, we will deliver it on the mixer truck with your concrete. Make sure you tell your Customer Service Representative what you need. Garrott Brothers offers a variety of finishing products check out our product link to learn more.
Set time depends upon several factors. The weather is the biggest factor. The temperature of the concrete is critical to set times. When the air temperature dips below 60ºF, you may need to add an accelerant to the concrete to help it reach the correct temperature. The relative humidity also impacts set times. When the humidity is high, concrete drying slows down. Different batches of concrete are designed to set up within differing time frames.
It is a common practice to add water to re-temper the concrete once it arrives on the job site, especially in hot weather. However, adding water will impact the slump and strength of the concrete by directly effecting the water to cement ratio.
The best thing you can do is to learn and practice the concrete finishing and curing standards that are spelled out by the American Concrete Institute (ACI).
Check out our products page for a complete list. Call our office for pricing.
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