CN104891846A

CN104891846A - Special accelerator for coal gangue-based sprayed concrete

Info

Publication number: CN104891846A
Application number: CN201510265128.5A
Authority: CN
Inventors: 刘刚; 张培莉; 李亮; 马英
Original assignee: XUZHOU CUMT BACKFILL TECHNOLOGY Co Ltd
Current assignee: XUZHOU CUMT BACKFILL TECHNOLOGY Co Ltd
Priority date: 2015-05-22
Filing date: 2015-05-22
Publication date: 2015-09-09

Abstract

The invention discloses a special accelerator for coal gangue-based sprayed concrete, belonging to a sprayed concrete accelerator. The accelerator is a powdery material prepared from aluminum oxygen clinker and active mineral by adding a small amount of composite modifier and through the processes such as levigation and homogenization, wherein the accelerator master batch accounts for 41-57wt%, the active mineral accounts for 27-40wt%, and the composite modifier accounts for 20-25wt%; and the composite modifier is composed of sulfate and naphthalene sulfonate formaldehyde polymer. According to the special accelerator for particular sprayed concrete in which coal gangue with fine particle size directly replaces gravel in common sprayed concrete and serves as aggregate, the problems such as slow condensation, low early strength, large later strength loss and high rebound rate in the preparation of coal gangue sprayed concrete using common accelerator are improved, and the cost of roadside support raw materials is lowered; and meanwhile, pollution of a mining area caused by coal gangue is reduced, and resource utilization of the coal gangue is realized.

Description

The special accelerating chemicals of a kind of bastard coal ground mass sprayed concrete

Technical field

The present invention relates to a kind of shotcrete accelerator, particularly the special accelerating chemicals of a kind of bastard coal ground mass sprayed concrete.

Background technology

Main using sprayed concrete as supporting and retaining wall in underground works and geotechnical engineering at present, be mainly used in roadway support within coal mines.The aggregate used in general sprayed concrete is sand and stone, needs outsourcing.And in coal production process, creating a large amount of solid waste-coal gangues, China increases the coal gangue of 3 ~ 400,000,000 t every year newly.The stacking of a large amount of coal gangue not only takies good farmland and ploughs, and its soluble substance permeates the ground, and can pollute groundwater in mining area, and coal gangue spontaneous combustion simultaneously can produce a large amount of obnoxious flavoures and dust, the eubiosis in havoc mining area.

If can using coal gangue as the sand gathered materials in alternative concrete and stone, can not only Cost of Concrete be reduced, increase economic efficiency, also achieve the recycling of coal gangue, waste recycles the utilization of having saved valuable first resource, has certain social benefit.

After broken coal gangue gather materials to have compared with sandstone that particle diameter is little, silt content large, mineral composition and the feature such as complex chemical composition, less robust, there are the problems such as rate of set is slow, early strength is low, later strength loss is large, rebound degree is large when preparing coal gangue sprayed concrete with common sprayed concrete accelerating chemicals used.

Summary of the invention

The object of the present invention is to provide the special accelerating chemicals of a kind of bastard coal ground mass sprayed concrete, the outstanding problem that the condensation of materials speed occurred when solving common accelerating chemicals preparation spoil base sprayed concrete is slow, early strength is low, later strength loss is large, rebound degree is large,

The object of the present invention is achieved like this: this accelerating chemicals: select aluminum oxide clinker and active mineral, then add a small amount of composite modifier, through techniques such as levigate, homogenizing, and a kind of pulverulent material made; The weight percent of each raw material consists of: accelerating chemicals masterbatch 41% ~ 57%, and active mineral is 27 ~ 40%, and composite modifier is 20% ~ 25%, and wherein composite modifier is made up of Sulfates and naphthalene sulphonate formaldehyde polymkeric substance.

Described accelerating chemicals masterbatch is aluminum oxide clinker, presetting period≤1min, final setting time≤5min, after grinding, reach 200 orders.

Described active mineral is metakaolin, Al ₂o ₃+ SiO ₂content > 85%, activity index>=110%, fineness is 200 orders.

Described composite modifier is Sulfates, and Sulfates is technical grade sodium sulfate or S-WAT, effective content >=98%.

Naphthalene sulphonate formaldehyde polymkeric substance in described composite modifier is naphthalene series high-efficiency water-reducing agent, and described water reducer is naphthalene sulfonic salt, technical grade, effective content >=99%.

Beneficial effect, owing to have employed such scheme, by the special accelerating chemicals of a kind of bastard coal ground mass sprayed concrete of said ratio, the spoil base sprayed concrete meeting performance of operating condition requirement can be produced, solve that common accelerating chemicals preparation spoil base sprayed concrete faces early stage and the problem such as later strength is low, setting and harden is slow, rebound degree is high, coal gangue is turned waste into wealth, while recycling spoil, also reduces support material cost.

Advantage: the abundant raw material source of the special accelerating chemicals of described bastard coal ground mass sprayed concrete, preparation method is simple, only need stir homogenizing, is applicable to suitability for industrialized production; The special accelerating chemicals rate of set of described bastard coal ground mass sprayed concrete is fast, and later strength fraction is high, significantly can improve the long durability of spoil base sprayed concrete; The special accelerating chemicals of described bastard coal ground mass sprayed concrete is used widely using sprayed concrete at colliery main roadway, tunnel etc. in the engineering of supporting and retaining wall.

Embodiment

This accelerating chemicals: select aluminum oxide clinker and active mineral, then add a small amount of composite modifier, through techniques such as levigate, homogenizing, a kind of pulverulent material made; The weight percent of each raw material consists of: accelerating chemicals masterbatch 41% ~ 57%, and active mineral is 27 ~ 40%, and composite modifier is 20% ~ 25%, and wherein composite modifier is made up of Sulfates and naphthalene sulphonate formaldehyde polymkeric substance.

Naphthalene sulphonate formaldehyde polymkeric substance in described composite modifier is naphthalene series high-efficiency water-reducing agent, solid content >=99%.

Embodiment 1: accelerating chemicals formula rate: aluminum oxide clinker 41.7%, metakaolin 33.3%, vitriol 16.7%, naphthalene sulfonic salt water reducer 8.3%.

Coal gangue sprayed concrete proportioning (mass ratio) is cement: coal gangue: accelerating chemicals is 1:5.75:0.03, and water cement ratio is 0.46, according to the method preparation coal gangue sprayed concrete of normal wet sprayed concrete.

Embodiment 2: accelerating chemicals formula rate: aluminum oxide clinker 57.4.0%, metakaolin 20.2%, vitriol 14.3%, naphthalene sulfonic salt water reducer 8.2%.

Comparative example 1:

Sprayed concrete proportioning (mass ratio) cement: stone: sand: common accelerating chemicals is 1:2:2:0.03, water cement ratio is 0.42.According to the method preparation sprayed concrete of normal wet sprayed concrete.

Comparative example 2:

Above-mentioned example and comparative example are carried out time of coagulation, rebound degree, uniaxial compressive strength and compressive strength rate to detect, the results are shown in Table 1.

Table 1

Claims

1. the special accelerating chemicals of bastard coal ground mass sprayed concrete, is characterized in that: this accelerating chemicals: select aluminum oxide clinker and active mineral, then add a small amount of composite modifier, through techniques such as levigate, homogenizing, and a kind of pulverulent material made; The weight percent of each raw material consists of: accelerating chemicals masterbatch 41% ~ 57%, and active mineral is 27 ~ 40%, and composite modifier is 20% ~ 25%, and wherein composite modifier is made up of Sulfates and naphthalene sulphonate formaldehyde polymkeric substance.

2. the special accelerating chemicals of bastard coal ground mass sprayed concrete according to claim 1, its feature: described accelerating chemicals masterbatch is aluminum oxide clinker, presetting period≤1min, final setting time≤5min, after grinding, reach 200 orders.

3. the special accelerating chemicals of bastard coal ground mass sprayed concrete according to claim 1, is characterized in that: described active mineral is metakaolin, Al ₂o ₃+ SiO ₂content > 85%, activity index>=110%, fineness is 200 orders.

4. the special accelerating chemicals of bastard coal ground mass sprayed concrete according to claim 1, it is characterized in that: described composite modifier is Sulfates, Sulfates is technical grade sodium sulfate or S-WAT, effective content >=98%.

5. the special accelerating chemicals of bastard coal ground mass sprayed concrete according to claim 1, it is characterized in that: naphthalene sulphonate formaldehyde polymkeric substance in described composite modifier, it is characterized in that described naphthalene sulphonate formaldehyde polymkeric substance is naphthalene series high-efficiency water-reducing agent, described water reducer is naphthalene sulfonic salt, technical grade, effective content >=99%.