The Benefits of Using SINAK Lithium Cure or S-102 for Curing
(As compared to other curing methods)
A. Introduction
The reason we cure concrete is because the environment within and immediately surrounding newly placed concrete has a direct influence on the hydration of cement in the concrete. Optimum hydration of the cementitious (Portland cement) components improves the desirable properties of the concrete. Until recently there have been 3 accepted ways to cure concrete; full soak water curing (optimal but impractical and costly), blanket curing (not as good as water soak and resource intensive and costly) and membrane curing compounds (fast and easy upfront but high back end costs and reduced quality concrete). Now there are now 2 solutions; SINAK Lithium Cure and S-102.
B. Comparison of conventional curing methods and SINAK
(I). Membrane Forming Curing Compounds
a. Background - The qualification for curing compounds in modern construction is simple and straight forward. Curing compounds are tested to determine how much of the initial “water-of-convenience” is retained in the concrete for the first few hours after the concrete has firmly set. The number is quantified and any product capable of “passing” this qualification is stated to conform to this standard (The most common being ASTM C309, ASTM C1315). What isn’t covered or recognized in these standards are that these test methods are performed under laboratory conditions only, the subsequent steps necessary for the other trades in dealing with the left over membrane and/or the residue left by these products; can be costly as well as potentially compromising the design strength.
This is where the advantages of SINAK are realized.
b. Advantages of SINAK are:
(i). No residue. SINAK curing products do not leave a film or residue like C309 products that require removal – and potential damage to the newly placed concrete surface, which usually requires the following:
Note: Each of these additional steps add cost and time to every project, sometimes adding as much as a week in unnecessary delays as well as costs sometimes exceeding the cost of the originally specified floor installation.
(ii). Strength gain of the surface should be anticipated. Tests show that treated surfaces are stronger and reduced permeability in comparison to other curing methods. Makes no waste.
1.
Both the Lithium Cure and S-102 are consumed by the concrete and has lasting benefits in the form of additional cement structure. Membrane forming curing compounds are removed by dissipating or mechanical removal therefore having no lasting benefits because they are not consumed they make waste.
2.
Neither Lithium Cure nor S-102 requires the use of waste producing preparation methods such as chemical removal or mechanical scarification.
(II) Blanket Curing & Full Soak Water Curing
a. Background – The assumed best curing method is wet curing. Either constantly ponding water or by using moisture-retaining coverings placed as soon as they won't damage the surface of the concrete. They are immediately saturated to wet the surface. It's important-that the covering remain wet for the duration of the curing period, with no periods of drying out. This procedure is intended to keep any moisture from leaving the slab, starting from the moment it's placed.
(i). Ponding water:
1. Pros:
a. Less labor intensive than Ponding method
b. Uses less water than Ponding method
2. Cons:
a. White reflective materials must be used keep the surface cool
b. A hot, windy environment makes maintaining blankets and water on the surface difficult. Blankets must be secured to the surface from all sides to ensure 100% contact
c. Placement and monitoring is difficult and labor intensive
d. Limited use of each blanket creates waste
e. Storage, cleaning and handling of blankets
f. Blanket residue may be apparent on the surface
(ii). Blanket Curing:
1. Pros:
a. Ensures 100% surface contact with water
b. Cooling effect for the concrete
2. Cons:
a. Difficult to obtain and maintain since water will go to the lowest spots or runoff
b. Excess water is an environmental hazard due to the contamination from concrete
b. Advantages of using Lithium Cure or S-102 are:
(i). Both add pozzolanic properties (additional cementing properties to the surface).
(ii). Both add bulking to the concrete surface, by adding additional cement structure that becomes a permanent part of the concrete.
(iii). Both provide long-term benefits including (increased surface density, strength, mar resistance, no mechanical preparation, etc.), whereas curing compounds can actually reduce strength as compared with water cure, give no long-lasting benefits, and require costly removal and preparation from their usage.
(iv). Makes no waste.
1.
Each full soak curing of a 100m2 slab uses (wastes) on average 5-7,000 gallons of water. It is anticipated that blankets may use less water. No water is used in either the Lithium Cure or S-102 process unless the application is vertical then a 1gallon of water is used per 100m2.
2.
With blanket curing you have waste (burlap/blanket), and plastic, however with both the Lithium Cure and S-102 the product is completely used within the concrete and the packaging is biodegradable, recyclable and/or reusable.
C. Effects on Micro-silica concrete
(I) Micro-silica concrete is used primarily in oil and gas facilities due to its higher compressive strength, durability, and it ability to withstand the intense cyclic and dynamic loads incurred during expansion and contraction of piping systems and stresses and strains of high revving equipment. Micro-silica is secondary cement that requires the formation of calcium hydroxide from the primary Portland cement to initiate the reaction of the micro-silica.
a. SINAK curing products combine with the calcium hydroxide to create more silica structure that helps insure the densification and the formation of additional cement structure.
b. Lithium Cure and S-102 are the only known alternatives that have been proven to provide the results obtained during full soak water curing of concrete and even outperforming water-curing in some testing, all at a fraction of the cost and time even in the most adverse conditions.
D. Summary Proper curing prevents moisture loss and maintains an adequate temperature for the hydration process. In addition, extending the duration of the curing period beyond that required to achieve the specified compressive strength allows for the maximum degree of hydration and will minimize the occurrence of defects that can impact serviceability. While long-term curing may not always be feasible using water curing techniques, both Lithium Cure and S-102 will provide the same or better results than full soak and blanket curing and allow you to access your surface in as little 1 day and to coat after 5 days without any special surface preparation.
