The "General Portland Cement" standard was jointly issued by the General Administration of Quality Supervision, Inspection and Quarantine and the National Standardization Committee on November 9, 2007.
The standard was completed on the basis of a large number of experiments and multiple solicitations, mainly combining the previous three national standards of GB175-1999, GB1344-1999 and GB12958-1999, in terms of technical requirements, variety and amount of mixed materials, Significant changes have been made in the qualification judgment, especially in the areas of cement classification, type of mixed materials, cancellation of P.O32.5, increase of cement ex-factory certificate content, etc., detailed examination of GB175-2007 "General Portland cement is explained in the standard provisions.
GB 175-2007/XG1-2009 "General Portland Cement" National Standard No. 1 revised the original GB175-2007 "General Portland Cement" related data and classification. Now the "general Portland cement" is based on GB 175-2007/XG1-2009 "general Portland cement".
General purpose Portland cement
Common Portland Cement
A hydraulic cementitious material made of Portland cement clinker and appropriate amount of gypsum and a specified mixed material.
Portland cement clinker
The raw material containing CaO, SiO2, Al2O3, and Fe2O3 is ground to a fine powder and then partially melted to obtain a hydraulic gelling substance having calcium silicate as a main mineral component. The calcium silicate mineral is not less than 66%, and the mass ratio of calcium oxide to silicon oxide is not less than 2.0.
PO cement
power level
The strength grade of Portland cement is divided into six grades of 42.5, 42.5R, 52.5, 52.5R, 62.5 and 62.5R.
The strength grade of ordinary Portland cement is divided into four grades of 42.5, 42.5R, 52.5, and 52.5R.
The strength grades of slag Portland cement, pozzolan Portland cement, fly ash Portland cement, and composite Portland cement are classified into three grades: 32.5, 32.5R, 42.5, 42.5R, 52.5, and 52.5R.
Setting time
The initial setting of the Portland cement is not less than 45 min, and the final setting is not more than 390 min;
Ordinary Portland cement, slag Portland cement, pozzolanic Portland cement, fly ash Portland cement and composite Portland cement are initially set at not less than 45 min, and the final setting is not more than 600 min.
Stability
The boiling method is qualified.
Fineness
(selective indicator)
Portland cement and ordinary Portland cement are expressed by specific surface area, not less than 300m2/kg; slag Portland cement, pozzolanic Portland cement, fly ash Portland cement and composite Portland cement It is indicated that the 80μm square hole sieve has a margin of no more than 10% or a 45μm square hole sieve and no more than 30%.
These beads are coated with a special coating materials, during the manufacture of the glass beads, which will improve the characteristics of moisture-proof and adhesion of glass bead. In the way, the life cycle of the glass beads can be prolonged and this enhances the beads reflectivity in a rainy night. These beads are usually used in white or yellow line-construction of highway.
The glass bead can be produced based on the standard of countries or areas, such as EN1423/1424, AASHTO M247, BS6088, JIS R3301 and KS L2521 etc.
Dual Coated Glass Beads,Dual Coated Glass Beads Roadmarking,Reflective Dual Coated Glass Beads,Dual Coated Glass Beads Traffic Paint
CHIYE GLASS BEAD (HEBEI) CO., LTD , http://www.chiyeglassbeads.com