CN102179875B - Still-free PHC tubular pile and production process thereof - Google Patents

Abstract

The invention provides a still-free petroleum hydrocarbon (PHC) tubular pile. Compared with the prior art, the tubular pile consists of the following components by weight: 340 to 420kg of cement, 100 to 160kg of mineral powder, 700 to 900kg of yellow sand, 1,030 to 1,260kg of broken stone, 2.0 to 6.0kg of water reducing agent and 60 to 130kg of water, wherein the particle size of the broken stone is 5 to 25mm. The invention also provides a production process condition and a production process parameter of the tubular pile, so that the tubular pile can still meet the requirement of a national regulation without high-pressure steam curing; the strength of concrete can reach 80MPa within 3 to 5 days, and the strength of the concrete is higher than the design strength of the concrete within 28 days; Rn is more than or equal to 1.15R which meets evaluation requirements according to a mathematical statistical method; and the problems that a pile body is cracked, a pile top is broken, and the like when the knocking frequency of a pile sinking hammer is more than 2,000 are solved.

Description

Exempt to press steaming PHC pile tube and production technology thereof

Technical field

The present invention relates to a kind of concrete product and production technology thereof, particularly relate to high strength concrete pile tube and production technology thereof.

Background technology

Short price is low is widely used because of it has preferably mechanical property, pile cycle for the PHC pile tube, the side of replacementing comprehensively in the engineering by land, on the water application in engineering more and more widely, replacement side progressively.Along with the high speed development that marine traffic engineering is built, the demand of PHC stake increases year by year, and owner and designing unit also have higher requirement to the performance and the quality of pile tube simultaneously.There are two kinds of situations in present domestic PHC pile tube on using: 1) user generally believes that the PHC pile tube must pass through high-pressure steaming and cultivating, and quality is just secure; 2) concrete strength is all represented to go out still intensity on the traditional product certificate.But there are two problems in high-pressure steaming and cultivating: temperature was very high when 1) the PHC pile tube went out still, if handle without effective cooling, then the temperature difference is enough to make concrete piles to produce the crack; 2) high-pressure steaming and cultivating can cause concrete fragility to increase.3) high-pressure steaming and cultivating need be than higher production input.Therefore, a kind of PHC pile tube production technology that can extensively use is provided, makes it, become present industry problem demanding prompt solution through the steam-cured requirement that just can satisfy each item index and related specifications of normal pressure.

Summary of the invention

Because producing crack, the high fragility of concrete and production, the temperature difference drops into bigger problem easily to high-pressure steaming and cultivating PHC pile tube; The invention provides a kind of steaming PHC pile tube of exempting to press; Form by cement, breeze, yellow ground, rubble, water reducer, water; Different with prior art is that said composition proportion does, cement 340 ~ 420kg, breeze 100 ~ 160kg, yellow ground 700 ~ 900kg, rubble 1030 ~ 1260kg, water reducer 2.0kg ~ 6.0kg, water 60 ~ 130kg, said ballast grain sizes are 5 ~ 25mm.The concrete strength of PHC pile tube, anti-hammering performance, injection performance etc. are all closely related with the proportioning of concrete material itself; So the inventor according to different raw material to these Effect on Performance; Optimization has obtained more rational concrete proportioning on existing raw material basis, thereby guarantees only steam-cured high-strength of the C80 level that just can reach under atmospheric pressure state of pile tube product.

As optimum condition of the present invention; Water reducer is a polyocarboxy acid type; Since the Cracking of High Flowing Concrete prepared of polycarboxylic acid series high efficiency water reducing agent through the time loss little, do not have slump-loss in one hour basically, two hours through the time lose less than 15%; So preferably this water reducer can further improve the concrete slump, guarantees subsequent use quality of concrete.

The present invention also provides the technology of producing this non-evaporating foster PHC pile tube, may further comprise the steps:

A. the cement described in the claim 1 is stored more than 3 days in advance, and temperature is lower than 50 ℃ when guaranteeing to use;

B. the water described in the claim 1 is heated to 40 ~ 60 ℃;

C. recheck each raw material described in the claim 1, stir more than the 140s, the concrete that obtains the slump and be 70 ~ 120mm is subsequent use;

D. under 15 ~ 45 ℃, concrete is gone into mould;

E. matched moulds stretch-draw;

F. with rotating speed low-speed centrifugal 2 ~ 4min of 100 ~ 150n/min, then respectively with the rotating speed of 400 ~ 500n/min and the centrifugal 5 ~ 8min of rotating speed middling speed and the 8 ~ 11min of 600 ~ 700n/min, at last with rotating speed high speed centrifugation 10 ~ 15min of 1000 ~ 1300n/min;

G. the pile tube that obtains was at first left standstill 1 ~ 2 hour, heated up then 3 hours, under 60 ~ 85 ℃ of constant temperatures steam-cured 6 ~ 8 hours, lower the temperature at last more than 3 hours;

H. remove mould.

Through preliminary treatment to concrete material cement and water, and the optimization of concrete mixing time, thereby guaranteed that the raw concrete slump is between 70 ~ 120mm.In subsequent process; Through control concrete molding temperature, parameter of noncentricity and steam-cured parameter control, optimized whole production technology, obtain the pile tube of demoulding strength greater than 75MPa; Thereby guarantee that pile tube is not carrying out under the condition of high-pressure steaming and cultivating, still can meet the requirement of national regulation.Guarantee that 3-5 days concrete strengths reach 80MPa, intensity was higher than the concrete design strength in 28 days.Satisfy Rn >=1.15R by mathematical statistics method evaluation requirement.While cracking resistance moment of flexure and the equal overgauge value of ultimate bending moment.Guarantee that it problems such as pile body cracking, stake bursting damage still do not occur when pile sinking hammering number hits greater than 2000.

The specific embodiment

Embodiment 1

At first cement being marched into the arena in advance stored more than 3 days, and temperature is lower than 50 ℃ of uses when guaranteeing to use; Heat water to 40 ~ 60 ℃ then, recheck, and be that rubble, the polyocarboxy acid type water reducer of 5 ~ 25mm mixes with cement of handling well and water with breeze, yellow ground, particle diameter, more than the stirring 140s, the concrete that obtains the slump and be 70 ~ 120mm is subsequent use; Concrete is lowered to mould at 15 ~ 45 ℃; Matched moulds stretch-draw; With rotating speed low-speed centrifugal 2 ~ 4min of 100 ~ 150n/min, then respectively with the rotating speed of 400 ~ 500n/min and the centrifugal 5 ~ 8min of rotating speed middling speed and the 8 ~ 11min of 600 ~ 700n/min, at last with rotating speed high speed centrifugation 10 ~ 15min of 1000 ~ 1300n/min; Obtain the pile tube of one-step forming just; The pile tube that obtains was at first left standstill 1 ~ 2 hour, heated up then 3 hours, under 60 ~ 85 ℃ of constant temperatures steam-cured 6 ~ 8 hours, lower the temperature at last more than 3 hours, remove mould, obtain the pile tube of intensity greater than 75MPa.

In order further to detect the influence of non-evaporating foster technology to pile tube, we are employed in stretch-draw in the same mould, and adopt identical system stake situation, keep the manufacturing difference of two pile tubes only to be embodied in last steam-cured process.Wherein pile tube SYZ-1 is through high-pressure steaming and cultivating, and pile tube SYZ-2 is without crossing high-pressure steaming and cultivating.Then with above-mentioned two root canal piles according to " Standard for test methods of concrete structures " (GB50152-92), " pretensioned prestressed concrete pipe pile " (GB3476-2009), " pretensioned prestressed concrete pipe pile " regulation in (ZJ3H007-2007); Deflection value to cracking resistance moment of flexure value, ultimate bending moment value, crazing-resistance test and the failure test of pile tube detects; And further to the crack time of occurrence; The width that position and crack the occur detection that makes an experiment, correction data is following:

Have the data that go up in the table can see that the actual measurement cracking resistance moment of flexure of non-evaporating foster PHC pile tube is 119.4% of a theoretical cracking resistance moment of flexure, the actual measurement ultimate bending moment is 135.1% of a theoretical limit moment of flexure.

Obtain according to crazing-resistance test and crack test simultaneously, span centre oar degree is respectively 9.41mm and 97.55mm when non-evaporating foster PHC pile tube appearance and destruction, and maximum crack width is 1.60mm.Therefore after adopting technical scheme provided by the present invention, pile tube is not carrying out under the condition of high-pressure steaming and cultivating, still can meet the requirement of national regulation.

Afterwards; We entrust bay, Shanghai construction quality to detect Co., Ltd, and non-evaporating foster PHC pile tube has been carried out the pile sinking test, through high strain and low strain detecting; According to " port engineering stake mechanomotive force detects rules ", show that pile body to be detected all reaches I class stake level.

Though institute can guarantee that still 3 ~ 5 days concrete strengths reach 80MPa in order to avoid press steaming PHC pile tube to save high-pressure steaming and cultivating technology, intensity was greater than the concrete design strength in 28 days.Satisfy Rn >=1.15R by mathematical statistics method evaluation requirement.While cracking resistance moment of flexure and the equal overgauge value of ultimate bending moment.Guarantee that it problems such as crack, stake bursting damage still do not occur when pile sinking hammering number hits greater than 2000.

Claims (3)

1. exempt to press steaming PHC pile tube; Form by cement, breeze, yellow ground, rubble, water reducer, water; It is characterized in that: said composition proportion does; Cement 340 ~ 420kg, breeze 100 ~ 160kg, yellow ground 700 ~ 900kg, rubble 1030 ~ 1260kg, water reducer 2.0kg ~ 6.0kg, water 60 ~ 130kg, said ballast grain sizes are 5 ~ 25mm;

And be prepared from following steps:

A. above-mentioned cement is stored more than 3 days in advance, and temperature is lower than 50 ℃ when guaranteeing to use;

B. above-mentioned water is heated to 40 ~ 60 ℃;

C. recheck each above-mentioned raw material, stir more than the 140s, the concrete that obtains the slump and be 70 ~ 120mm is subsequent use;

D. under 15 ~ 45 ℃, concrete is gone into mould;

E. matched moulds stretch-draw;

F. with rotating speed low-speed centrifugal 2 ~ 4min of 100 ~ 150n/min, then respectively with the rotating speed of 400 ~ 500n/min and the centrifugal 5 ~ 8min of rotating speed middling speed and the 8 ~ 11min of 600 ~ 700n/min, at last with rotating speed high speed centrifugation 10 ~ 15min of 1000 ~ 1300n/min;

G. the pile tube that obtains was at first left standstill 1 ~ 2 hour, heated up then 3 hours, under 60 ~ 85 ℃ of constant temperatures steam-cured 6 ~ 8 hours, lower the temperature at last more than 3 hours;

H. remove mould.

2. the pressure of exempting from as claimed in claim 1 is steamed the PHC pile tube, and it is characterized in that: said water reducer is the polyocarboxy acid type water reducer.

3. a production exempting from according to claim 1 or claim 2 pressed the technology of steaming the PHC pile tube, it is characterized in that may further comprise the steps:

A. the cement described in the claim 1 is stored more than 3 days in advance, and temperature is lower than 50 ℃ when guaranteeing to use;

B. the water described in the claim 1 is heated to 40 ~ 60 ℃;

C. recheck each raw material described in the claim 1, stir more than the 140s, the concrete that obtains the slump and be 70 ~ 120mm is subsequent use;

D. under 15 ~ 45 ℃, concrete is gone into mould;

E. matched moulds stretch-draw;

F. with rotating speed low-speed centrifugal 2 ~ 4min of 100 ~ 150n/min, then respectively with the rotating speed of 400 ~ 500n/min and the centrifugal 5 ~ 8min of rotating speed middling speed and the 8 ~ 11min of 600 ~ 700n/min, at last with rotating speed high speed centrifugation 10 ~ 15min of 1000 ~ 1300n/min;

G. the pile tube that obtains was at first left standstill 1 ~ 2 hour, heated up then 3 hours, under 60 ~ 85 ℃ of constant temperatures steam-cured 6 ~ 8 hours, lower the temperature at last more than 3 hours;

H. remove mould.