Basic Standards of Concrete ACI Basic Standards of Concrete ACI
Concrete ACI allows you to know the standards that are used for structures that are made of concrete. Aside from the aggregates, the chief ingredient in making concrete is usually Portland cement, so named because the material looks like the color of natural limestone that is mined from the Isle of Portland. It is an island that can be found on the English Channel. However, the use of concrete requires different applications and properties on cement materials, which include, aside from Portland, hydraulic and blended cements.
Portland Cement Types
The Standard Specification for Portland Cement identifies eight Portland types of cements. Portland is a material that is chiefly composed of hydraulic calcium silicates, and it belongs to the hydraulic cement variety.
Blended Cement Types
Blended cements are formed from the integration of two or more kinds of materials. The mixing is done uniformly and is composed of Portland cement, fly ash, blast furnace slag, calcined clay, silica fumes, hydrated lime and other pozzolans.
Standards and Specifications
The test methods and specifications used for cement are usually developed by organizations that have a national scope. In the United States, the organization that sets the standards for cement is the ASTM, while in Canada, it is the CSA. When a certain type of cement is specified for a construction project, there should be a consideration on the kind of materials that are found on the particular location. Such a consideration should have the flexibility to allow for either blended or Portland cement to be used. The use of pozzolans and slag cements that are available locally should also be considered as long as the desired properties of concrete can be attained. If possible, any kind of cement that meets the standards of the project should be considered. Special or unique kinds of cements should not be considered unless they are specifically needed.
Different chemical and physical requirements are used in the production of different kinds of cement. Currently, there are 3 common standards for hydraulic cement that are used for general construction purposes in the United States. These three are different from each other.
- ASTM C150: used in the specification of Portland cement
- ASTM C595: used in the specification of hydraulic blended cements
- ASTM C1157: used in the performance specification of hydraulic cements
Each of these standards is used for providing specifications on different cement types. They each have their uses in a construction project.
A survey that compares the features of different kinds of cements that are available commercially was made back in 2004, and the results were released in a report 4 years later. The data include information on Portland cements, ASTM C1157 hydraulic cements and blended cements. It also includes data on stucco, masonry and mortar cements. The survey discussed the physical and chemical properties of cements and compared the present information with what is available historically to be able to determine any trends. The complete report can be downloaded from the Internet. The compressive strength of ASTM C109 was used for the comparison of different cement types for general construction. ASTM C150, C1157 and C595 were found by the survey to have strengths that are comparatively the same.