Temperature extremes make it difficult to properly cure concrete. On hot days, too much water is lost by evaporation from newly placed concrete. If the temperature drops too close to freezing, hydration slows to nearly a standstill. Under these conditions, concrete ceases to gain strength and other desirable properties. In general, the temperature of new concrete should not be allowed to fall below 50 Fahrenheit (10 Celsius) during the curing period.
Begin by considering the cost of the driveway over its lifetime. A good quality concrete driveway will last more than 30 years with little or no maintenance. Asphalt driveways need periodic sealing and coats to retard age related cracking. Even properly constructed residential asphalt driveways will deteriorate more quickly due to environmental influences than due to vehicle traffic. If you consider the cost of surface and crack sealers and the shorter life-span of the asphalt, concrete will cost much less.
The sub-base should be well compacted to ensure no further settlement will occur. The soil should be well graded so the concrete is evenly placed and a minimum of concrete is needed. Moisture is also an important factor to consider. If the soil is too dry, it will draw the water out of the concrete, causing it to crack. If the soil is too wet, the concrete may not dry evenly or at a quick enough rate. Over-wet soil may also settle after the concrete has cured.
Steel-wire brushes should be used with care because they can leave metal particles on the surface that later may rust and stain the concrete. Wet methods involve the application of water or specific chemicals according to the nature of the stain. The chemical treatment either dissolves the staining substance so it can be blotted up from the surface of the concrete or bleaches the staining substance so it will not show. To remove blood stains, for example, wet the stains with water and cover them with a layer of sodium peroxide powder; let stand for a few minutes, rinse with water and scrub vigorously. Follow with the application of a 5 percent solution of vinegar to neutralize any remaining sodium peroxide.