Early strength agent, early strength water reducer application range
TIME：2019-07-11 READER：330
1. Early strength agent and early strength water reducer are suitable for steaming concrete and concrete construction with early strength requirements under normal temperature, low temperature and lower temperature than -5 °C. It is not advisable to use early strength agents and early strength water reducers under hot environmental conditions.
2. Chemical substances that are harmful to the human body or contaminated by the environment after being mixed with concrete are strictly prohibited as early strength agents. Early strength agents containing harmful components such as hexavalent chromium salts and nitrites are strictly prohibited for use in drinking water projects and food contact projects. Ammonium nitrates are strictly prohibited for use in construction projects such as office and residence.
3. It is strictly forbidden to use early strength agent and early strength water reducing agent prepared with chlorine salt in the following structures:
(1) Prestressed concrete structure;
(2) Structures used in environments with relative humidity greater than 80%, structures at locations where water levels change, open-air structures, and structures that are often washed by water and washed by water;
(3) large volume concrete;
(4) Direct contact with structures of acids, bases or other aggressive media;
(5) Reinforced concrete prefabricated components that are often steamed at temperatures above 60 °C;
(6) Concrete with decorative requirements, especially for concrete with uniform color or metal decoration on the surface;
(7) Thin-walled concrete structures, beams, trusses, drop hammers and forging hammer concrete foundations of intermediate and heavy-duty working cranes;
(8) Structures using cold drawn steel bars or cold drawn low carbon steel wires;
(9) The aggregate has an alkali-active concrete structure.
4. It is strictly forbidden to use early strength agent and early strength water reducer containing strong electrolyte inorganic salts in the following concrete structures:
(1) the structure of the contact part with galvanized steel or aluminum-iron, and the structure with exposed steel bars embedded with iron parts without protective measures;
(2) The structure using a DC power supply and the structure within 100 m from the high-voltage DC power supply.
5. Early strength agent containing potassium and sodium ions should be used for concrete with alkali activity in aggregate. It should meet concrete in contact with water or in humid environment. When alkali active aggregate is used, it will be brought in by admixture. The alkali content (in equivalent sodium oxide) should not exceed 1kg/m3 concrete, and the total alkali content of concrete should meet the requirements of relevant standards.
2. Chemical substances that are harmful to the human body or contaminated by the environment after being mixed with concrete are strictly prohibited as early strength agents. Early strength agents containing harmful components such as hexavalent chromium salts and nitrites are strictly prohibited for use in drinking water projects and food contact projects. Ammonium nitrates are strictly prohibited for use in construction projects such as office and residence.
3. It is strictly forbidden to use early strength agent and early strength water reducing agent prepared with chlorine salt in the following structures:
(1) Prestressed concrete structure;
(2) Structures used in environments with relative humidity greater than 80%, structures at locations where water levels change, open-air structures, and structures that are often washed by water and washed by water;
(3) large volume concrete;
(4) Direct contact with structures of acids, bases or other aggressive media;
(5) Reinforced concrete prefabricated components that are often steamed at temperatures above 60 °C;
(6) Concrete with decorative requirements, especially for concrete with uniform color or metal decoration on the surface;
(7) Thin-walled concrete structures, beams, trusses, drop hammers and forging hammer concrete foundations of intermediate and heavy-duty working cranes;
(8) Structures using cold drawn steel bars or cold drawn low carbon steel wires;
(9) The aggregate has an alkali-active concrete structure.
4. It is strictly forbidden to use early strength agent and early strength water reducer containing strong electrolyte inorganic salts in the following concrete structures:
(1) the structure of the contact part with galvanized steel or aluminum-iron, and the structure with exposed steel bars embedded with iron parts without protective measures;
(2) The structure using a DC power supply and the structure within 100 m from the high-voltage DC power supply.
5. Early strength agent containing potassium and sodium ions should be used for concrete with alkali activity in aggregate. It should meet concrete in contact with water or in humid environment. When alkali active aggregate is used, it will be brought in by admixture. The alkali content (in equivalent sodium oxide) should not exceed 1kg/m3 concrete, and the total alkali content of concrete should meet the requirements of relevant standards.
