The invention discloses an alkali-free liquid accelerator for sprayed concrete, which relates to a liquid accelerator. The invention solves the technical problem that the existing powdered accelerator is large in dust, and the long-term strength of the existing powdered accelerator is reduced because the existing powdered accelerator has alkalinity. The alkali-free liquid accelerator for sprayed concrete is composed of the following raw materials in parts by weight: aluminum sulfate, organic amine, attapulgite, bentonite and water. The accelerator disclosed by the invention has an alkali-free advantage and has no excitant odor, not only can greatly reduce the possibility of producing alkali-aggregate reaction, but also has no physical harm to constructors; the accelerator disclosed by the invention has a great strength effect, the 28-day strength of concrete is reduced less even not reduced, and a higher one-day strength and a higher 4-hour strength can be obtained; and the accelerator disclosed by the invention is good in low temperature resistance and not crystallized and solidified, and still has good liquidity at a temperature of -15 DEG C, so that a nozzle is not plugged, and the normal running of sprayed construction under low temperature conditions is ensured.

Alkali-free liquid accelerator for sprayed concrete

PURPOSE: A manufacturing method of a mineral liquid accelerating agent is provided to increase stability and quick setting power by combining cement mineral raw material with alkali-free accelerating agent, thereby improving performance, usability and human-body harmfulness of accelerating agent for shortcrete. CONSTITUTION: A manufacturing method of a mineral liquid accelerating agent comprises the steps of: manufacturing a mixture by mixing calcium slufo aluminate, aluminum hydroxide, phosphoric acid, and water (S1); manufacturing a solution by dissolving the mixture from the previous step in hydrofluoric acid (S2); manufacturing a mixed solution of calcium sulfo aluminate, aluminum hydroxide, and slufoaluminum in the solution from the previous step (S3); controlling pH of the mixed solution by adding a pH controller in the mixed solution from the previous step (S4); and stabilizing the mixed solution by injecting a stabilizer (S5). The mineral liquid accelerating agent comprises: 4-6 wt% of Al(OH)3; 2-4 wt% of calcium sulfo aluminate; 0.2-0.9 wt% of phosphoric acid group; 8-10 wt% of HF; 47- 50 wt% of Al2(SO4)3); 0.5-0.8 wt% of sodium; 0.4-0.6 wt% of amines; 1.0-2.5 wt% of magnesiums; and 28-32 wt% of water. [Reference numerals] (AA) Start; (BB) Dissolve a mixture in hydrofluoric acid; (CC) Dissolve aluminium sulfate; (DD) Control pH; (S1) Mixing calcium slufoaluminate and aluminum hydroxide; (S4) Add stabilizer; (S5) End

Mineral based liquid quick setting agent and method for manufacturing thereof

The embodiment of the invention provides a waterproof construction method of a drainage ditch. The waterproof construction method comprises the steps: a concrete base face of the drainage ditch is pre-treated; an HDPE sheet is fixed to the pre-treated concrete base face; a waterproof layer is applied to the upper layer of the HDPE sheet; and after the waterproof layer is cured, a prefabricated cover plate is placed at the open position of the drainage ditch. According to the waterproof construction method of the drainage ditch, the HDPE sheet is fixed to the pre-treated concrete base face, thewaterproof layer is applied based on the HDPE sheet, thus the purpose of preventing leakage of the drainage ditch can be achieved, the structural reliability of the drainage ditch is improved, and the safety of a tunnel structure is guaranteed.

Waterproof construction method of drainage ditch

The invention discloses an early high-strength composite alkali-free liquid setting-accelerator, a preparation method and shotcrete. The alkali-free liquid setting-accelerator comprises the followingcomponents in percent by weight: 45%-55% of aluminum sulfate; 5%-10% of active hydrogen hydroxide aluminum; 5%-10% of a fluoride salt; 1.5%-4% of an alcohol amine; 0.5%-1% of polyacrylamide; 1%-3% ofan organic water-reducing agent; 0.8%-1% of a stabilizer; and 25%-35% of water.

Early high-strength composite alkali-free liquid setting-accelerator, preparation method and shotcrete

PURPOSE: A concrete accelerating agent is provided to secure liquid stability under oversaturation of aluminum oxide and sulfate ion, and to show excellent quick setting power, cohesive property and early strength by increased content of aluminum oxide and sulfate ion. CONSTITUTION: A manufacturing method of a concrete accelerating agent comprises the steps of: manufacturing aluminum hydroxide solution by dissolving a mixture comprising aluminum hydroxide in hydrofluoric acid (S1); manufacturing mixed solution of aluminum hydroxide and aluminum sulfate by dissolving aluminum sulfate in the aluminum hydroxide solution (S2); and controlling pH of the mixed solution and injecting a stabilizer (S3). In the step S1, sulfuric acid is more added when adding the hydrofluoric acid. The stabilizer is a reaction stabilizer for increasing reaction stability, and comprises amines. The stabilizer is an oversaturated liquid stabilizer for securing stability of the mixed solution, and comprises manesiums. The concrete accelerating agent comprises: 8-15 wt% of Al(OH)3; 0.1-0.5 wt% of phosphoric acid group; 16-18 wt% of HF; 1.5-2.5 wt% of magnesiums; and 20.30 wt% of water. [Reference numerals] (AA) Start; (BB) End; (S1) Dissolving hydrofluoric acid; (S2) Dissolving aluminum sulfate; (S3) Controlling pH and injecting a stabilizer

Quick setting agent and method for manufacturing thereof

PURPOSE: A liquid accelerator compositions for shotcrete and the shotcrete comprising the same are provided to exhibit excellent quick-setting and bonding properties as well as long-term intensity CONSTITUTION: A liquid accelerator compositions for shotcrete comprises 5-15wt% of metakaolin, 30-40wt% of aluminium sulfate, 1-5wt% of amines, 3-10wt% of aluminium hydroxide, 4-10wt% of hydrofluoric acid, 05-2wt% of dispersing agent, and the remainder of water

Liquid accelerator compositions for shotcrete and shotecrete comprising the same

A drain system of a double floor plate for a tunnel is provided to improve stability of a road pavement structure, and to reduce construction period by reducing the construction process. A drain system of a double floor plate for a tunnel includes a drain layer(110) having an auxiliary base layer or an antifreeze layer spread on a tunnel floor, a drain plate(120) having an upper block installed in an upper part of the drain layer by longitudinally and horizontally spacing blocks, a column part tapered from a lower part of the upper block and extended downward and latticed drain passages formed in the lower part of the upper block by the space with sides and front and rear parts of the tapered column part, a lean concrete layer(130) charged in the block of the drain plate, and a pavement layer(140) formed in an upper part of the lean concrete layer. The column part is longitudinally extended by rounding front and rear parts, or collecting the front and rear parts into an apex, or forming streamlined front, rear and side parts.

Bae Gyu Jin

Papers

Liquid accelerator compositions for shotcrete and shotecrete comprising the same

Double floor drainage system for tunnel