trowel finish air entrained concrete

What is air entrained concrete? - findanyanswer.com

to hard-trowel air-entrained con- crete.The risks associated with this requirement include: ACI 302.1R-96, "Guide for Concrete Floor and Slab Construction," states that entrained air is not recommended for concrete to be given a smooth, dense, hard-troweled finish.

What is the difference between air entrained and non air ...

The risks associated with this requirement include: ACI 302.1R-96, "Guide for Concrete Floor and Slab Construction," states that entrained air is not recommended for concrete to be given a smooth, dense, hard-troweled finish.

Air Entrainment in Interior and Exterior Concrete Slabs

hard-troweled finish shall not contain an air-entraining admixture or have a total air content greater than 3 percent." The combination of air entrainment and a hard-troweled finish has been investigated and reported to be problematic since the 1980s.3 Yet, the occurrence of surface delaminations or blisters from finishing air-entrained ...

Air-Entrained Concrete Patching Mix AE - TCC Materials

voids left by the screed. Hard steel trowel finish is not recommended for air-entrained concrete. 3. Concrete shall be used and placed in final position within 1 hour after initial mixing or discarded at that time. 4. Allow the concrete to reach initial set, wait for all water to evaporate from the surface before finishing with a trowel or ...

Magnesium Hand Float 18" x 3-1/8 pair up with a 16"x4 ...

It is recommended for use with air entrained concrete. One of the reasons why this tool is so popular it is because it produces a smoother finish than wood. 2) A Concrete Finishing Trowel with measurements 16"x4"" and its main features are: Made of Stainless Steel; Cast Aluminum mounting securely riveted to tempered.

EZ Trowel™ Concentrate - Specco

EZ Trowel Concentrate forms a lubricating gelled surface film which reduces plastic shrinkage cracking and wind crusting and allows the surface to remain plastic for extended finishing time. EZ Trowel Concentrate can be used effectively on both air-entrained and non-air entrained concrete flatwork, and concrete mixes containing silica fume, fly ...

FINISHING NEWS

Steel trowel finishing air-entrained concrete results in the formation of horizontal delaminations in new concrete floors. Steel trowel fin-ishing concrete with more than 3% air can also result in surface de-laminations in new floors as well. The Canadian concrete standard CSA A23.1 warns of this problem

Avoid Surface Defects on Exterior Slabs | For Construction ...

Surface sealing is more likely to occur when using steel trowels or fresnos to finish air-entrained concrete. A fresno is a long-handled trowel with a 5-in.-wide and 24- …

Finishing air-entrained concrete requires a light touch ...

Finishing air-entrained concrete requires a light touch. Rachel Detwiler. July 27, 2021. Durability, Insights, Specifications. When finishing air-entrained concrete, less is more. Hard-troweled surfaces and air-entrained concrete don't mix. If you need to entrain air— that is, if the concrete will experience cycles of freezing and thawing ...

Concrete Delamination Repair | What Causes Concrete ...

Avoid applying dry shakes on concrete that contains air. Utilize accelerated or heated concrete to ensure uniform setting throughout the slab. Never install concrete on top of a vapor retarder if possible. If a trowel finish is required on an internal slab, avoid using air-entrained concrete.

Finishing Air-Entrained Concrete

The air voids again provide relief sites for the buildup of salt concentrations and the pressures that result due to concentration gradients. Other uses of air-entrained concrete include sulfate resistance, resistance to alkali-silica reactivity, and improved …

8 Types of Concrete Finishes [PDF] - The Constructor

Types of Concrete Finishes 1. Troweled Finish . Trowel finish is the most common and popular finish of concrete used for major types of applications. After the concrete is laid in the formwork and leveled, the trowel is used to smooth and fine-level the surface of concrete.

Concrete finishing with air entrained concrete ...

Concrete finishing with air entrained concrete. For durability reasons, I need to specify my concrete to meet certain chloride resistance requirements, and in the standard that I design to (CSA A23.1, probably almost verbatim ACI 350), the exposure class requires air entrainment. This is for a structurally reinforced suspended slab.

Finishing air entrained concrete - Structural engineering ...

For a new parking garage floor with specified 5% to 8% air entrained concrete, and a urethane waterproofing membrane 60 mils thick, a wood float finsh is too rough. The concrete requires a steel trowel finish according to the membrane manufacturers. CSA Standard S413 says that a "single pass" of the steel trowl is ok on the air entrained concrete.

Delamination of Troweled Concrete Surfaces | Sterling ...

Avoid dry shakes on air-entrained concrete. Use heated or accelerated concrete to promote even setting throughout slab depth. Avoid placing concrete directly on vapor retarders, if the application allows. Do not use air-entrained concrete for interior slabs that will receive a trowel finish.

Industry best practices hard troweling concrete with air

dense, hard-troweled finish because blistering or delamination may occur. These troublesome finishing problems can develop any time the total air content is in excess of 3%. 8.3.11 Air entrained concrete should never be used in any normal weight concrete floor slab that is to receive a hard troweled finish.

Air tests for non-air-entrained concrete

Note that it is recommended to require air content testing for non-air-entrained concrete used for floors and slabs. ACI 301-20 "Specifications for Concrete Construction" require the total air content of hard-troweled interior concrete floors to not exceed 3 percent. According to ACI 302.1R-15 "Guide to Concrete Floor and Slab ...

Walk-behind Trowels Article | Wacker

A concrete mix that contains more than three percent entrained air should be finished by utilizing hand tools and not be given a hard trowel finish with a power trowel. If the entrained air content is higher than three percent the floor can delaminate and cause problems in the finishing steps.

Only use Walk Behind Power Trowels for Lightweight Concrete

So the adage that you shouldn't use a power trowel on air-entrained. Concrete doesn't apply in the case of lightweight concrete; you can use a power trowel, but only with proper timing. A typical fire-rated lightweight mix calls for compressive strengths between 3500 and 4000 psi. Most lightweight concrete is pumped, with 4000-psi mixes ...

CIP 20 - Delamination of Troweled Concrete Surfaces

4. Avoid placing concrete directly on vapor retarders, if the application allows. 5. Do not use air-entrained concrete for interior slabs that will receive a trowel finish. 6. Avoid placing concrete on substrate with a temperature of less than 40° F (4° C). References 1. Guide for Concrete Floor and Slab Construction, ACI 302.1R

CIP 1 00 - CONCRETE IN PRACTICE

must be air-entrained. Severe exposures require air contents of 6 to 7 percent in freshly mixed concrete made with 3/ 4-inch [19 mm] or 1-inch [25-mm] aggregate. In moderate exposures, where deicing salts will not be used, 4 to 6 percent air will be sufficient. Air-entrained concrete of moderate slump (up to 5 inches [125 mm]) and adequate ...

COLD WEATHER CONCRETE GUIDE FOR STRUCTURAL …

• Avoid hard-trowel finishing air-entrained concrete (3% or greater) as this can lead to surface blistering or other surface defects. Therefore, air-entrained concrete should not be specified for hard-trowel slab construction.

Floated and trowelled finishes - Concrete

Power trowelling of air-entrained concretes is not recommended due to the risk of surface delamination. Also, trowelling before the bleed water has evaporated can lead to a risk of delamination. It is also difficult to get the power float and trowel up to a fixed edge/wall/cladding or a formed joint, therefore some hand finishing may be ...

Delamination of Troweled Concrete Surfaces — …

Do not use air-entrained concrete for interior slabs that will receive a trowel finish. Avoid placing concrete on substrate with a temperature of less than 40°F (4°C). References. Guide for Concrete Floor and Slab Construction, ACI 302. 1R American …

Air-entrained concrete for an indoor slab. : Construction

We have a design that calls for air-entrained concrete for a slab. The contractor would like to use non-air-entrained since it is easier to trowel and finish. The slab is indoors, however there is no heat source for the building (it is used as storage), and the climate will be well below freezing in the winter.

CIP 2 - Scaling Concrete Surfaces - Geiger Ready Mix

4. Use correct timing for all finishing operations and avoid the use of steel trowels for exterior concrete slabs. 5. Specify air-entrained concrete. In cold weather, concrete temperature should be at least 50°F [10°C], contain an accelerating admixture, and be placed at a lower slump.

Hard Trowel Finish on Air-entrained Concrete

states that entrained air is not recommended for concrete to be given a smooth, dense, hard-troweled finish. ASCC concrete contractors will hard-trowel air-entrained concrete if required by specification, but only with the acknowledgment that the risk associ-ated with delamination or blistering and the changes in hardened air void parameters ...

(Delamination due to use of air entrainment in a concrete ...

(Delamination due to use of air entrainment in a concrete slab that has received a machine-trowel finish): Cross section of a concrete core from a delaminated slab showing the near-surface region ...