ASTM Standard on limestone blended cement

ASTM International has published ASTM C595-12, Standard Specification for Blended Hydraulic Cements.

The recent revision defines requirements for a new cement type:  Type IL, portland-limestone blended cement, which includes more than 5% and up to 15% limestone as an ingredient. 

This technology has the potential to reduce environmental impact of cement production by about 10% while maintaining performance characteristics concrete producers are familiar with. Similar cements have been used in Europe and other places around the world for several decades and have demonstrated the performance and durability expected in concrete products.

For the most recent editions of the specifications, please visit the following websites:

AASHTO: https://bookstore.transportation.org/
ASTM: http://www.astm.org/Standards/C595.htm

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Concrete to prevent floor covering failures

Developed and patented by USC Technologies, Inc., a wholly-owned subsidiary of U.S. Concrete,Inc, Aridus(R) Rapid Drying Concrete is the first ready-mix concrete solution for preventing floor covering failures, an industry-wide problem that cost millions of dollars annually in damage, downtime, repair and replacement.

The moisture from concrete is often overlooked as a leading cause of concrete floor covering failures. Aridus(R) proprietary concrete mix helps prevent moisture problems by drying faster than conventional concrete mixes, allowing flooring materials to be installed on concrete in 30 days or less.

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A lesson for structural engineers

While researchers have long known of the incredible strength of spider silk, the robust nature of the tiny filaments cannot alone explain how webs survive multiple tears and winds that exceed hurricane strength.

Now, a study that combines experimental observations of spider webs with complex computer simulations shows that web durability depends not only on silk strength, but on how the overall web design compensates for damage and the response of individual strands to continuously varying stresses.

Engineered structures are typically designed to withstand large loads with limited damage, but extreme loads are more difficult to account for. The spider has uniquely solved this problem by allowing a sacrificial member to fail under high load. One of the first questions a structural engineer must ask is ‘What is the design load?' For a spider web, however, it doesn't matter if the load is just strong enough to cause failure, or one hundred times higher--the net effect is the same. Allowing a sacrificial member to fail removes the unpredictability of 'extreme' loads from the design equation."

For detailed information on NSF-supported research elsewhere in Massachusetts, see results for Massachusetts on Research.gov.

Ref: NSF Press Release 12-016:  A Spider Web's Strength Lies in More Than its Silk

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Holcim patent: using waste heat from clinker cooler

Switzerland based Holcim Technology Ltd filed patent application for method for treating alternative, carbon-containing, low-caloric waste materials for use in furnace systems. The inventors are Ernst Frank and Obrist Albert.

According to the Controller General of Patents, Designs & Trade Marks, "In a method for treating alternative, carbon-containing, low- caloric waste materials for use in furnace systems, in particular rotary tubular kilns for the production of clinker, the carbon-containing, alternative fuels are subjected to high- temperature gasification under anoxic conditions at temperatures above 1000C, wherein water, water vapor or CO2 is injected to ensure a reaction forming CO and H2. The waste heat from a clinker cooler is used for the high-temperature gasification."

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