Rapid Set® Cement is the primary component of dozens of cements, concrete, mortars, and grouts developed for specific applications. Since we (CTS Cement Manufacturing Corp.) introduced the product in the mid-1970s, state transportation departments have consumed more than 2 million tons for bridge and highway panel replacement, partial- and full-depth pavement rehabilitation, and emergency repairs. All but four allow Rapid Set® products.

Rapid Set® isn’t portland cement, though, so you can’t use ASTM C150 (Standard Specification for Portland Cement) to write a specification. That’s why ASTM C1600 (Standard Specification for Rapid Hardening Hydraulic Cement) was introduced in 2009. We recommend a prescriptive rapid-strength concrete specification based on ASTM C1600 cement and adding maximum allowed shrinkage to your other concrete performance requirements (e.g., freeze-thaw, permeability, etc.). Click here for assistance from our engineering sales team.

The cement shall be Rapid Set® cement manufactured by CTS Cement Manufacturing Corp.

• The cement shall be a calcium sulfoaluminate (CSA) cement with at least 20% CSA and at least 40% belite.
• The cement shall be a belitic calcium sulfoaluminate (BCSA) cement with no addition of portland cement.

The cement shall meet the requirements of ASTM C1600 – VRH (very rapid hardening).

• Compressive Strength: The concrete shall achieve 3000 psi (27.58 MPa) compressive strength at 3 hours.
• Flexural Strength (Highway Pavement): The concrete shall achieve 400 psi (2.76 MPa) flexural strength at 2 hours.
• Flexural Strength (Airfield Pavement): The concrete shall achieve 550 psi (3.79 MPa) flexural strength at 4 hours.

Given how detrimental shrinkage is to concrete’s long-term durability, states have begun doing just that. Here's an example:

• The concrete shall not exceed 0.04% shrinkage at 28 days per ASTM C157 (Standard Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete) as modified below.
  • The demold time shall be determined by ASTM C403 (Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance) Final Set plus 25% of that time.
  • Initial measurement shall be taken immediately after demolding.
  • The shrinkage specimens shall be air-cured until they have reached an age of 28 days.
• The time to cracking shall exceed 60 days per ASTM C1581 (Standard Test Method For Determining Age At Cracking And Induced Tensile Stress Characteristics Of Mortar And Concrete Under Restrained Shrinkage).