Substrate Requirements, Compressive and Cohesive Testing
ACT 2170™ Substrate Requirements; Concrete Must Be:

Sound;
a) 2,000 psi compressive minimum; Schmidt Hammer test
b) 200 psi cohesive; pull-off; Elcometer test
c) Absorptive, water drop test
d) Comply with ACI 201 Overall conclusion

Water Drop Test: There does not appear to be any “official” governing standard to this test as it is a superficial surface test only, but still a fast and inexpensive method of determining concrete
absorbance.

AC•Tech 2170 requirement: Concrete must be absorbent;

This very simple test will tell you if the concrete substrate is absorbent or not.  We require an absorbent substrate for our epoxy moisture system to penetrate into the cap of the concrete to perform  properly. If the concrete is nonabsorbent, then there will be no penetration and there very likely be bonding issues with the system. It is best to perform this test after mechanical preparation, but may be done prior to check the effectiveness of the prep work.

Opening the AC•Tech 2170™ FC - 2.4 gallon cans

Basic Cement/Concrete Information

Cement VS Concrete:
Cement is to concrete as flour is to a cake mix. While this analogy is very simplistic, it is applicable and accurate. Cement, whichever type, is never used by itself, but in combination with other materials such as sand, slag and other additives or chemicals and water (the cement paste) plus aggregate (stone) to make the collective mix of concrete. The cement is the “binder” or “glue” that holds the  concrete matrix together.  Critical to the performance of any given concrete element is the water/cement (w/c) ratio or the ratio of water to the cement paste. Hardened concrete is the dimensional solid that is the result of the chemical reaction of the concrete mixture and water or hydration (curing) process of this cement paste, concrete mixture.

General Concrete Curing:

Curing can be described as keeping the concrete moist and warm enough so that the hydration of cement can continue. More elaborately, it can be described as the process of maintaining satisfactory moisture content and a favorable temperature in concrete during the period immediately following placement, so that the hydration of the cement may continue until the desired properties are developed to a sufficient degree to meet the service requirement.

If curing is neglected in the early period of hydration, the quality of concrete will experience a sort of irreparable loss. An efficient curing in the early period of hydration can be compared to a good and wholesome feeding given to a newborn baby.

Moisture in Concrete, General Information

Hydrostatic VS. Water Vapor:

Hydrostatic: In concrete slab or floor work, hydrostatic (water) pressure is caused by water in the liquid phase, which is entering the structure through cracks, wall-to-floor joint or some other construction defect and is visible as water, i.e. ponding on the interior floors (rain water through windows excluded); as visible water. 

Water Vapor: Liquid water in the gas phase, which can readily permeate a semi-permeable  substrate such as concrete. Water vapor is water in the gas or vapor phase and is not visible either as “wet” areas or “ponded” water; you cannot see water vapor.

Alkalinity in Concrete Slabs; The Real Culprit

In general the flooring industry believes “concrete moisture related” floor failures are due to high moisture vapor emission rates (MVER) and/or moisture content. In 1996, FCICA (Floor Covering Installation Contractors Association) research found that alkalinity plays a major role in flooring failures.

Defined: pH or the “potential of Hydrogen”, is the measure of how acidic (low pH) or alkaline (high pH) any given solution is where a pH of 7 is neutral. Healthy concrete has a high pH ~12.0 – pH 13.3. Alkalinity forms as a result of Portland cements reaction with water during the hydration phase. The excess (alkaline saturated) mix water moves towards the surface forming capillaries throughout the concrete. As the concrete “dries out”, calcium hydroxide remains inside these capillaries.

Cracks in Concrete Slabs

I. There are two basic types of “natural” and one man-made cracks in concrete slabs:
A. Moving or Dynamic:
• Random cracks
• Expansion joints
• Settling cracks

B. Non-Moving or Static Cracks:
• Shrinkage cracks
• Spider cracking
• Control cuts

C. Damage or Impact Cracks
• May be moving depending on the extent of the impact
• May be repaired

ASR in Concrete Slabs

What the Experts Say;
I. PCA; (the Portland Cement Association): Alkali-silica reaction (ASR) “…In ASR, aggregates containing certain forms of silica will react with alkali hydroxide in concrete to form a gel that swells as it adsorbs water from the surrounding cement paste or the environment. These gels can swell and induce enough expansive pressure to damage concrete.”

Concrete Surface Preparation;

Grinding as a floor preparation:

Grinding has not been generally acceptable as a method for mechanical substrate preparation when using the AC•Tech 2170™ Water Vapor Reduction Systems, but with innovations in the technology of grinding machines and the diamond plates they use, this form of mechanical preparation can be acceptable, provided the profile of the prepared concrete is acceptable, consistent and dust-free.

Concrete Floor Preparation Parameters & Publications:

ACI 302.2R-06; Guide for Concrete Slabs that Receive Moisture-Sensitive Flooring Materials; ACI Committee 302; ISBN: 9780870312205; 2006; Order Code: 302206.

Abstract; ACI 302.2R-06: This guide contains materials, design, and construction recommendations for concrete slabs-on-ground and suspended slabs that are to receive moisture-sensitive flooring materials. These flooring materials include sheet rubber, epoxy coatings, vinyl composition tile, sheet vinyl, carpet, athletic flooring, laminates, and hardwood.  Chapters 1 through 8 provide an understanding of concrete moisture behavior and drying, and show how recommended construction practices can contribute to successful performance of floor covering materials. This background provides a basis for the recommendations in Chapter 9 to improve performance of floor covering materials in contact with concrete moisture and alkalinity.

CORE TESTING, DESCRIPTIONS AND PROCEDURES:

Question: Why should I do any testing at all? This is a common question that many applicators ask. Usually the answer comes when a problem has manifested itself on a just completed floor-coating
project. In the litigious atmosphere in today’s floor contracting world the better question would be “why would I not test?” Testing is a way the installer can take a “snapshot” of the condition, content
and make-up of the concrete that is about to be coated. By testing for various constituents, or contaminates in the concrete, the applicator is making sure that the concrete to be coated is in fact
sound and in a condition that will allow for the application of coatings1. (I.e. adhesion or bonding issues, silicates, weak cap, ASR, etc.). With the information that the test results will reveal, the
applicator is better armed to be pro-active with potential problems or any additional work that may be necessary to successfully remediate or complete the project. AC•Tech strongly suggests that under
certain circumstances core testing be conducted to protect the applicator, final flooring installer, the final customer, and to validate our 15 – year warranty.

BRIEF INSTRUCTIONS FOR APPLICATION OF the AC•Tech 2170™

Water Vapor Reduction Systems

The AC•Tech 2170™ is a one-coat; easy to apply system that can deliver a floor with finished resilient flooring in as little as 1 day (depending on the size of the floor and the size of the available work crew and AC Tech product used).

What is Dew Point?

“Moisture Proofing” Bolt Holes and Perforations in The AC•Tech 2170™

When drilling holes in a concrete deck where the AC•Tech 2170™ has been applied and to maintain the monolithic integrity of the moisture barrier, please use the following procedure
as a guideline;

Un-Reacted Silicates In a Paragraph

This bulletin refers to sodium and potassium silicates that are introduced into (or onto) the concrete via a curing compound, densifier/hardener or as another brand of moisture vapor reduction system either introduced to the concrete as an additive to the mix design or topically sprayed on. These products are “reactive” in nature and are supposed to completely react with the constituents in the concrete matrix, which never seems to happen, and it is these “un-reacted” silicates that will give us trouble.

ASTM F1869 Moisture Testing Protocol: Abstract

Significance and Use:
Use this test method to obtain a quantitative value indicating the rate of moisture vapor emission from a concrete floor and whether or not that floor is acceptable to receive resilient floor covering. The moisture vapor emission rate only reflects the condition of the concrete floor at the time of the test. All concrete subfloors emit some amount of moisture in vapor form. Concrete moisture emission is a natural process driven by environmental conditions. All floor coverings are susceptible to failure from excessive moisture vapor emissions. The moisture vapor emitted from a concrete slab is measured
in pounds. This measurement is the equivalent weight of water evaporating from 1000 ft2 of concrete surface in a 24–h period. The calcium chloride moisture test has been the industry standard for making this determination and is a practical, well-established and accepted test of dynamic moisture. It will produce quantified results directly applicable to flooring manufacturer’ specifications. The results obtained reflect only the condition of the concrete floor at that time.

ASTM F2170 ASTM F 2170 RH (Relative Humidity)

Testing Protocol:
ASTM Abstract:

Significance and Use

Moisture permeating from concrete floor slabs affects the performance of flooring systems such as resilient and textile floor coverings and coatings. Manufacturers of such systems generally require moisture testing to be performed before installation on concrete. Internal relative humidity testing is one such method.  Excessive moisture permeating from floor slabs after installation can cause floor covering system failures such as de-bonding and deterioration of finish flooring and coatings and microbial growth.  Moisture test results indicate the moisture condition of the slab only at the time of the test.

Calcium Chloride v. In-situ Relative Humidity

By: George Donnely Testing & Inspections; (Revised 12/11)

A discussion on the differences and Pros & Cons of these two types of moisture testing; Moisture passing from or through concrete has become the number one cause of floor covering system
failure in this country. Most U.S. producers of floor coverings, adhesives and resinous coatings have historically looked to the calcium chloride method of testing concrete slabs to determine dryness and suitability for the installation of their products. The American Society for Testing and Materials (ASTM) has written a standard for the use of anhydrous calcium chloride when testing dryness of concrete. The standard's most current version is also known as ASTM F 1869-11. Some floor covering manufacturers are now either suggesting or requiring the use of in-situ relative humidity data as the preferred method of determining concrete dryness. ASTM has also published a standard test method for the use of in-situ relative humidity probes, the test's current version and designation is ASTM F 2170-11. This test method involves measuring relative humidity levels inside of the concrete slab and finds it's basis in testing commonly performed in Europe. ASTM F 710 offers recommendations regarding the suitability of a concrete slab for the installation of resilient floor coverings based on results achieved by these test methods. This standard states that moisture vapor emission, per ASTM F 1869, should not exceed 3 pounds per 1,000 square feet per 24 hours, unless otherwise specified by the flooring or adhesive manufacturer. The standard continues by stating that relative humidity inside of a concrete slab should not exceed 75%, per ASTM F 2170, unless otherwise specified by the flooring or adhesive manufacturer.  There is a growing number of floor covering manufacturers requiring both tests be performed prior to installing floor coverings.

Grinding as A Concrete Floor Preparation Method

Grinding has not been generally acceptable as a method for mechanical substrate preparation when using the AC•Tech 2170™ Water Vapor Reduction Systems, but with innovations in the technology of grinding machines and the diamond plates they use, this form of mechanical preparation can be acceptable, provided the profile (CSP value) of the prepared concrete is acceptable, consistent and dust-free.

Alkalinity and its Consequences for floor adhesives and most flooring material

In the presence of moisture, alkalinity is always an integral part of concrete or other cement based materials. The degree to which alkalinity exists depend largely on the composition of the cement used for construction.  Primarily responsible for high alkalinity levels are highly soluble metal oxides such as Potassium and Sodium Hydroxides. Calcium hydroxide also contributes to alkalinity, but often to a lesser extent.

Certified Floor-Covering Consultants

Certified Moisture Testing * Forensic Flooring Failure Investigations

Bill Lepito:

Certified Floor-Covering Consultants (CFCC) is a nationally recognized certified independent moisture testing firm. We specialize in Forensic Flooring Failure Investigations, and Moisture Testing of
concrete substrates in preparation for the installation of moisture sensitive adhesives, floor coverings, and coatings.

ASTM F3010-13 | Standard Practice for Two-Component Resin Based Membrane-Forming Moisture Mitigation Systems for Use Under Resilient Floor Coverings

ASTM F710-11 | Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring

ASTM E96 | Standard Test Methods for Water Vapor Transmission of Materials

Above-Slab Alkalinity & Moisture Vapor Barrier in compliance with ASTM F3010-13 Standard Practice for Two-Component Resin Based Membrane-Forming Moisture Mitigation Systems

Performance Specification Based on ASTM F3010 for Moisture Mitigation and pH Control

Contractor's Point-of-View on Need for Performance Specifications

Fast Cure. Alkaline insensitive to pH levels of 14 sustained. Moisture Mitigation for RH levels of 100% (ASTM F2170) and 25+ lbs MVER (ASTM F1869).

COMPLIANCE TESTED by Berkeley Analytical. Certificate #140527-01 Issued 5.27.2014

Reference Standard: California Department of Public Health CDPH/EHLB/Standard Method Version 1.1, 2010

Standards & Codes Recognizing CDPH Standard Method V1.1 (partial list)
 USGBC LEED for Schools, 2009
 USGBC LEED Version 4, BD&C, ID&C, 2013
 Collaborative for High Performance Schools (CHPS), National Core Criteria, 2013
 ANSI/GBI 01-2010, Green Building Assessment Protocol

Fast Drying Primer for Cementitious Self-Leveling Underlayments, Patches, and Wear Surfaces Over Non-Porous Substrates.

ASTM F3010 compliance requires less than 0.1 Perms as tested under ASTM E96

ACTech 2170 15 Year Material and Labor Warranty

SDS | Part A | ACTech 2170™ FC Fast Curing Epoxy Moisture Barrier for Concrete Slab | Moisture Mitigation and Alkalinity Control for Commercial Flooring

SDS | Part B | ACTech 2170™ FC Fast Curing Epoxy Moisture Barrier for Concrete Slab | Moisture Mitigation and Alkalinity Control for Commercial Flooring

SDS | ACTech 2170™ SLP Fast Drying Primer for Cementitious Self-Leveling Underlayments, Patches, and Wear Surfaces Over Non-Porous Substrates 

Oct 2017 Blog -- From the Contractor's View - Risk

Select Moisture Mitigation Products with Your Crew's Health & Safety in Mind.