|
What Makes For a Good
Installation of Pervious Concrete?
- Evaluate the soil. Take test borings to establish whether soil will support the right subbase and the pervious pavement. Soils that contain significant levels of silt or clay that are either highly compressible, lack cohesion or will expand or contract with the absorption of moisture may not be suitable for concrete pavement unless remediation steps are taken to stabilize the soil. Engineering is an important part of successful pervious pavement. If roots or other organic debris remain the soil will later settle, and the pavement will crack. Have soil condition certified before placing subbase.
- Base preparation. Before concrete is placed the subbase must be compacted using a vibratory roller or other suitable equipment to a minimum density of 90% to 98%. The compacted base must be moist prior to the placement of paving material, but no puddles of free standing water can be tolerated. Properly prepared bases will not become rutted by ready mix trucks.
Properly compacted base supports the weight of a fully loaded, ready-mix truck without creating ruts.
Mix design. Pervious mixture suppliers must employ high quality control. Pervious mixes contain Portland cement, a nominal 3/8" Florida limerock aggregate, admixtures and minimum water as designed. Almost all fine aggregate is eliminated from the mix to provide the necessary voids to allow the penetration of water. Typically pervious concrete has about 70% of the density of standard concrete paving mixtures. The amount and timing of the addition of water to the mix is critical. Too much water will carry the cement slurry to the base of the pavement creating a barrier that prevents storm water from passing into the subbase and substrate. Too little water prevents bonding of the aggregate to the cementitious mixtures.
- Placement. Subbase must be compacted to specification. Ruts created by equipment or vehicles prior to placement must be eliminated and recompaction must be employed. Forms must be set to specified grades. Rail mounted leveling equipment should be aligned and in place prior to beginning placement. The material should be discharged from the trucks as rapidly as possible and feasible. After leveling, the paved area must immediately be rolled using a full length roller and supplemental rollers as needed. All equipment must be close at hand for quick access.
- Curing. Following placement, the pervious concrete should be covered with polyethylene film which should be held down securely. Curing time without vehicular traffic is a minimum of seven days.
- Use only qualified placement contractors. Charger Enterprises, Inc. has a number of successful large pervious concrete jobs to its record. Our background includes site preparation work as well. We have engineering contacts throughout the state to support any project, any way appropriate. We work with the best material suppliers in the area who consistently supply us with the most uniform, high quality pervious mixtures.
| For a good installation, sufficient trained manpower is a must. Each team member has an assigned task that must be performed with precision timing. |
|
Avoid the problems inexperience
or improper installation can cause:
Unqualified concrete installers, who probably do not have the right equipment or understand Pervious placement requirements. You can’t learn Pervious installation from a textbook or short course. We have more than 20 years experience with Pervious Concrete. We do our Pervious installations within our family run company. We don’t subcontract it out.
- Uncorrected soil conditions. Be sure that base preparation is certified as being up to engineered specification. All organic materials must have been removed from soil under base. Proper drainage must be established if Pervious Concrete is to function as designed.
- Undetected bad concrete mixes. Experience is the best teacher. We almost always can spot bad mixes immediately and reject them.
- Lack of the use of qualified engineering. Don’t rely on firms that do not have successful experience with Pervious Concrete. If the base soil is not properly tested and evaluated, and if the Pervious Concrete Base is not properly designed for drainage and stability, the system will not perform as intended. This is the responsibility of engineer. The base should be certified by him before the Pervious Concrete is placed.
- Unqualified Test Laboratories. If the lab does not have years of experience with Pervious Concrete you are playing Russian roulette. Most inexperienced labs try to use test methods that do not address the unique characteristics of Pervious Concrete.
DO IT RIGHT THE FIRST TIME! CALL
THE PERVIOUS CONCRETE EXPERTS AT CHARGER ENTERPRISES TODAY!
For More Information Contact:
|
||||||||||||
|
|
|||||
| Copyright 2000-2005 by Charger Enterprises, Inc. ALL RIGHTS RESERVED.
All other trademarks are the properties of their respective owners. |
