Methods for Improving Limestone Utilization in Concrete

Tech ID: 24670 / UC Case 2013-080-0

Summary

Researchers at UCLA have improved the utilization of limestone in concrete by developing a system for tailoring the processing parameters to achieve pre-defined mechanical properties and designing processing conditions that enhance the reactivity of the limestone additives.

Background

Concrete is one of the most widely used and produced materials in the world. However, concrete production adds roughly 5-8% of all CO2 emissions globally. Issues concerning the sustainability of cement have led researchers to investigate other raw materials for concrete, such as limestone. Adding limestone to the mixture changes the mechanical properties of the resultant concrete based on many factors such as the limestone/cement ratio, the limestone particle size, and the rate of hydration. The final mechanical properties must be manually tested after production to understand the effect that the input limestone parameters had on the final product. Furthermore, limestone in concrete mixtures is typically present in conditions that leave it in an unreactive state that limits its versatility.

Innovation

UCLA researchers from civil engineering, materials science and engineering, and the school of sustainability have developed methods for improving the use of limestone in concrete. A system was developed that marries the final mechanical properties of the concrete to the initial input parameters of the concrete mixture. The amount of limestone content and particle size can be tailored to predict a desired set of mechanical properties without the need for experimental testing. In addition, concrete processing conditions have been established that increase the reactivity of limestone in order to create carboaluminates that broaden the range of mechanical properties achievable with limestone additives.

Applications

  • Predict concrete mechanical properties from selected processing parameters
  • Determine processing parameters from experimentally tested mechanical properties
  • Adjust processing parameters (particle size, content, etc.) while maintaining the desired mechanical properties
  • Design concrete with limestone having a broad range of achievable mechanical properties

Advantages

  • Predict mechanical properties from processing parameters 
    • No need to experimentally test mechanical properties after production 
  • Ability to increase limestone content while maintaining a desired mechanical property 
    • Decrease CO2 emissions 
  • Broaden the range of available mechanical properties in concrete with limestone

State Of Development

The toolkit capable of analyzing processing parameters has been developed and tested in-house. The concrete mixture conditions that enhance the reactivity of limestone have been simulated and in-house experiments are ongoing.

Patent Status

Country Type Number Dated Case
Patent Cooperation Treaty Reference for National Filings WO2014032018 02/27/2014 2013-080
 

Patent Pending

Related Materials

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Inventors

  • Sant, Gaurav

Other Information

Keywords

Concrete, Cement, Limestone, Processing Parameters, Surface Area, Particle Size, Hydration, Hardness, Strength, Elastic Modulus, Young’s Modulus, Carboaluminates, Reactivity

Categorized As

UCLA Technology Development Group
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Tel: 310.794.0558 | Fax: 310.794.0638 | ncd@tdg.ucla.edu