Concrete Alberta provides a number of Concrete Tech Tips to help navigate and troubleshoot issues and educate yourself on various concrete properties:
TECH TIP #1:
Dusting Concrete Surfaces
Chalking or powdering at the surface of a concrete slab is called dusting. The characteristics of such surfaces are...
TECH TIP #2:
Scaling Concrete Surfaces
Scaling is flaking or peeling of a finished hardened concrete surface as a result of exposure to cycles of freezing and thawing. Generally it starts as localized small patches, which later may merge and...
TECH TIP #3:
Crazing Concrete Surfaces
Crazing is the development of a network of fine random cracks or fissures on the surface of concrete or mortar caused by shrinkage of the surface layer. These cracks are...
TECH TIP #4:
Cracking Concrete Surfaces
Concrete, like other construction materials, contracts and expands with changes in moisture content and temperature and deflects depending on...
Cracking Concrete Surfaces PDF
TECH TIP #5:
Plastic Shrinkage Cracking
Plastic shrinkage cracks appear in the surface of fresh concrete soon after it is placed and while it is still plastic. The cracks appear mostly on...
Plastic Shrinkage Cracking PDF
TECH TIP #6:
Joints in Concrete
Although concrete expands and contracts with changes in moisture and temperature the general overall tendency is to shrink and, therefore, crack. Irregular cracks are unsightly and...
TECH TIP #7:
Cracks in Concrete Basement Walls
Cast-in-place concrete basements provide durable, high quality living space. Cracking of concrete is a natural occurrence and, at times...
Cracks in Concrete Basement Walls PDF
TECH TIP #8:
Concrete yield is the volume of freshly mixed, unhardened concrete made from a known quantity of ingredients. It is sold on a volume basis, usually in...
TECH TIP #9:
Low Concrete Test Cylinder Strength
Cylinders are molded from a sample of fresh concrete. Procedures must be in accordance with CSA standards. The average strength of the set...
Low Concrete Test Cylinder Strength PDF
TECH TIP #10:
Strength of In-Place Concrete
Drilled cores test lower than properly made and tested standard molded
100 by 200mm cylinders. This applies to all...
Strength of In-Place Concrete PDF
TECH TIP #11:
Curing In-Place Concrete
Curing is the maintaining of a satisfactory moisture content and temperature in concrete. Curing begins after placement and finishing so that the concrete may develop the desired...
TECH TIP #12:
Hot Weather Concreting
Hot weather, as defined by ACI 305R, is any combination of the following conditions that tends to impair the quality of freshly mixed ore hardened concrete by accelerating the rate of moisture loss and...
TECH TIP #13:
Blisters are hollow, low-profile bumps on the concrete surface typically from the size of a dime (10mm) up to...
TECH TIP #14:
Finishing Concrete Flatwork
Finishing is the operation of consolidating, leveling, and creating a concrete surface of a desired texture and hardness. The finish can be...
Finishing Concrete Flatwork PDF
TECH TIP #15:
Chemical Admixtures for Concrete
Admixtures are natural or manufactured chemicals added to the concrete before or during mixing. The most often used chemical admixtures are...
Chemical Admixtures for Concrete PDF
TECH TIP #16:
Flexural Strength of Concrete
It is the ability of a beam or slab to resist failure in bending. It is measured by...
Flexural Strength of Concrete PDF
TECH TIP #17:
Aggregate Pop Outs
A pop out is a relatively small conical shaped cavity left after a near-surface aggregate particle has expanded and fractured. Generally, part of the fractured aggregate particle will be found at...
TECH TIP #18:
Radon Resistant Buildings
Radon is a colorless, odorless, radioactive gas which occurs naturally in soils in amounts dependent upon the geology of the location. The rate of movement of radon through the soil is dependent primarily upon...
TECH TIP #19:
Curling of Concrete Slabs
Curling is the distortion of a slab into a curved shape by upward or downward bending of the edges. The occurrence is primarily due to differences in...
TECH TIP #20:
Delamination of Troweled Concrete Surfaces
In a delaminated surface, the top 20mm is densified and separated from the base slab by a thin layer of air or water. The delamination on the surface of a slab may range in size from...
Delamination of Troweled ... PDF
TECH TIP #21:
Loss of Air Content in Pumped Concrete
Increasingly, specifiers are requiring concrete to be tested for air content at the discharge end of concrete pumps at the point of placement in the concrete structure. In some cases, the air contents are...
Loss of Air Content in Pumped Concrete PDF
TECH TIP #22:
ACI defines grout as "mixture of cementitious material and water, with or without aggregate, proportioned to produce a pourable consistency without segregation of the constituents. Grout may also...
TECH TIP #23:
Discolouration is non-uniformity of colour or shading of hardened concrete surface. It may appear as spotted or...
TECH TIP #24:
Job Site Addition of Water
This the addition of water to ready-mixed concrete in a truck mixer after arrival at the location of the concrete placement. Such tempering of concrete may be done with a portion of...
Job Site Addition of Water PDF
TECH TIP #25:
Mortar flaking is the dislodging of small sections of surface concrete, usually smaller than a dime, directly above coarse aggregate particles. Mortar flaking is typically very...
TECH TIP #26:
Cold Weather Concreting
Since weather conditions can change rapidly in the winter months, good concrete practices and proper planning are critical...
TECH TIP #27:
Supplementary Cementing Materials (SCM's)
The principal cementitious material in most concrete mixes is portland cement. Today, most concrete mixtures contain...
TECH TIP #28:
Concrete Slab Moisture
Concrete slab moisture can cause problems with the adhesion of floor-covering material, such as tile, sheet flooring, or carpet and bond-related failures of non-breathable floor coatings. Many adhesives used for installation of floor coverings are...
TECH TIP #29:
Vapour Retarders Under Slabs on Grade
Vapour retarders are materials that will minimize the transmission of water vapour from the sub-slab support system into a concrete slab. Vapour retarders are typically...
Vapour Retarders Under Slabs on Grade PDF
TECH TIP #30:
Concrete Pre-Construction Conference
Prior to the start of a job, particularly a major project, a concrete pre-construction conference (sometimes referred to as a pre-pour meeting) should be held to define and allocate responsibilities of the entire construction team. It is imperative that...