CN105948609A - Determination method for mixing amount of expanding agent added into continuous reinforced concrete pavement - Google Patents

Abstract

The invention discloses a determination method for the mixing amount of an expanding agent added into a continuous reinforced concrete pavement. The method comprises the following steps: preparing test pieces with different amounts of the expanding agent; then drafting a relation curve of the mixing amounts of the expanding agent, crack widths and stress; and determining an optimal mixing amount according to the relation curve. The method is simple and quantitatively determines the mixing amount of the expanding agent to be added into a continuous reinforced concrete pavement; and the continuous reinforced concrete pavement with an optimal mixing amount of the expanding agent can prevent too large crack width of the continuous reinforced concrete pavement due to a too small mixing amount of the expanding agent and arching damage of the continuous reinforced concrete pavement due to a too large mixing amount of the expanding agent.

Description

A kind of continuous reinforced concrete pavement expansive agent dosage determines method

Technical field

The invention belongs to continuous reinforced concrete pavement field, be specifically related to a kind of continuous reinforced concrete pavement expansive agent dosage and determine Method.

Background technology

Chinese scholars studies discovery through for many years: compared to Portland cement concrete pavement, continuous reinforced concrete pavement (letter Claim CRCP) at longitudinally configuration continuity reinforcement(bar), do not set contracting seam, durability is greatly improved, and it is comfortable to drive a vehicle.But at Heavy Traffic and Under environmental factors effect, CRCP also there will be various disease, and wherein thrusting is the topmost form of expression.Thrust two spacing of finger The transverse crack of the least (less than 0.6m) and short longitudinal crack and pavement edge (or longitudinal seam) area defined and stripping The serious Y-shaped crack such as fall, crush.The horizontal micro-cracks at initial stage gradually develops change under vehicular load and environmental activity Width, extraneous salt and water enter at the bottom of plate, cause the erosion of road deck and reinforcing bar.Stripping under the effect of vehicular load, at crack Fall and support at the bottom of uneven plate can cause road deck horizontal tensile stress excessive, produce longitudinal crack, and then formation thrusts.Research Showing, CRCP fracture width is the biggest for thrusting impact.When crack is wide, the peeling meeting ratio at crack is more serious, at crack Load-transfer Capacity can reduce, and the tension caused under Vehicle Load in road deck increases, and causes the longitudinal cracking of plate, Jin Erzao One-tenth thrusts.Therefore typically fracture width is the biggest, thrusts the most.

In continuous reinforcement concrete, fill extender can reduce fracture width, and then minimizing thrusts.Expansive agent dosage is too small, no Can effectively reduce fracture width, it is impossible to effectively reduce and thrust；Otherwise, volume is excessive, then easily cause the destruction of arching upward of CRCP, Therefore it needs to be determined that the optimum mix amount of extender.But, the volume of current extender directly gives according only to experience.Such as document 1 (Lee Nine Soviet Unions, Liu Chaohui, Yao Jialiang. flyash, extender dual mixing technology improve the experimental study J China and foreign countries of continuous reinforcement concrete performance Highway, 2006, (3): 242-244) directly give an expansive agent dosage the most by rule of thumb, do not provide the process determined or depend on According to.Therefore, a kind of method quantitatively determining continuous reinforcement cement expansive material the optimum mix amount is the most still lacked.

Summary of the invention

It is an object of the invention to overcome above-mentioned deficiency, it is provided that a kind of continuous reinforced concrete pavement expansive agent dosage determines method, energy Enough quantitatively determine continuous reinforcement cement expansive material the optimum mix amount.

In order to achieve the above object, the present invention comprises the following steps:

Step one, the continuous reinforcement concrete sample under the different expansive agent dosage of preparation, measure and join continuously under different expansive agent dosage The strain of reinforced concrete drying shrinkage, temperature contracting coefficient；

Step 2, calculates the fracture width of continuous reinforced concrete pavement, stress under different expansive agent dosage；

Step 3, draws expansive agent dosage and fracture width, the relation curve of stress respectively；

Step 4, determines the optimum mix amount of extender according to relation curve.

In described step one, drying shrinkage strain, the mensuration of temperature contracting coefficient are obtained by cement concrete drying shrinkage, temperature contracting test； In dry shrinkage testing in curing box curing temperature be 20 ± 2 DEG C, relative humidity be 60 ± 5%；In temperature contracting test, test temperature exists Changing in the range of 0 DEG C～40 DEG C, temperature interval uses 10 DEG C, each temperature spot constant temperature 3h.

In described step 2, calculate the fracture width of continuous reinforced concrete pavement under different expansive agent dosage, stress method such as Under:

According to the drying shrinkage of continuous reinforcement concrete, temperature contracting coefficient under different expansive agent dosages, formula (1) is utilized to calculate continuous reinforcement The fracture width of concrete road surface, utilize formula (2) calculate continuous reinforced concrete pavement maximum stress:

${\mathrm{\μ}}_c=\frac{2({\mathrm{\α}}_c\mathrm{\Δ}T+{\mathrm{\ϵ}}_{sh})(b_2-b_1)}{b_1{r}_{3}cth\left(r_{3}L\right)-b_2{r}_{1}cth\left(r_{1}L\right)}---\left(1\right)$

${\mathrm{\σ}}_s{|}_{x=0}=E_c({\mathrm{\α}}_c\mathrm{\Δ}T+{\mathrm{\ϵ}}_{sh})\[\frac{b_2{r}_1\csc h\left(r_{1}L\right)-B_1{r}_3\csc h\left(r_{3}L\right)}{b_1{r}_3\csc h\left(r_{3}L\right)-b_2{r}_1\csc h\left(r_{1}L\right)}+1\]---\left(2\right)$

Wherein:

b₁=(a₁+a₂-r₁ ²)/a₁；

b₂=(a₁+a₂-r₃ ²)/a₁；

$a_1=\frac{{\mathrm{\πd}}_s{k}_s}{A_c{E}_c};$

$a_2=\frac{k_{c}b}{A_c{E}_c};$

$a_3=\frac{{\mathrm{\πd}}_s{k}_s}{A_s{E}_s};$

$r_1=\sqrt{\frac{1}{2}\[a_1+a_2+a_3+\sqrt{{(a_1+a_2+a_3)}^2-4a_2{a}_3}\]};$

r₂=-r₁；

$r_3=\sqrt{\frac{1}{2}\[a_1+a_2+a_3-\sqrt{{(a_1+a_2+a_3)}^2-4a_2{a}_3}\]};$

r₄=-r₃；

Wherein, μ_cFor continuous reinforced concrete pavement fracture width, unit is mm；σ_{S | x=0}For continuous reinforced concrete pavement Big stress, unit is MPa；α_cFor coagulation soil temperature contracting coefficient, unit is 10^-6/℃；Δ T is that temperature declines, and unit is DEG C；ε_sh For concrete dry shrinkage strain, unit is 10^-6；E_cFor modulus of elasticity of concrete, unit is Pa；L is the half of fracture interval, single Position is m；As is the area of reinforcement, and unit is m²；Ds is bar diameter, and unit is m；Es is reinforcing bar elastic modelling quantity, and unit is Pa；B is longitudinal reinforcement spacing, and unit is m；k_sFor the bonding stiffness coefficient between reinforcing bar and concrete, unit is Pa/m；k_cFor Frictional resistance coefficient between basic unit and surface layer, unit is Pa/m；H is surface thickness, and unit is m；Ac is concrete area, single Position is m²。

In described step 4, determine that the method for the optimum mix amount of extender is as follows:

For avoiding the destruction of arching upward of continuous reinforced concrete pavement, the maximum crushing stress value taking continuous reinforced concrete pavement is 3.22MPa, according to the relation curve in step 3, fracture width value is 0, value of compressive stress is less than expansion minimum during 3.22MPa Agent volume is the optimum mix amount.

Compared with prior art, the present invention is by the test specimen of the different extender of preparation, then draws expansive agent dosage and fracture width, answers The relation curve of power, determines the optimum mix amount finally according to relation curve, present invention determine that the method for expansive agent dosage is simple, and quantitatively Determine continuous reinforced concrete pavement expansive agent dosage value, can according to the continuous reinforcement concrete that the optimum mix amount interpolation extender is made Effectively prevent owing to expansive agent dosage value is very few and cause continuous reinforced concrete pavement fracture width relatively big and extender is mixed The continuous reinforced concrete pavement that value is excessive and causes arches upward destruction.

Accompanying drawing explanation

Fig. 1 is that embodiment of the present invention fracture width is with expansive agent dosage change curve；

Fig. 2 is that embodiment of the present invention concrete stress is with expansive agent dosage change curve.

Detailed description of the invention

The present invention will be further described below in conjunction with the accompanying drawings.

See Fig. 1 and Fig. 2, embodiment:

Step one, the continuous reinforcement concrete sample under the different expansive agent dosage of preparation, measure continuous reinforcement under different expansive agent dosage Concrete shrinkage coefficient, temperature contracting coefficient:

Coagulating cement is carried out according to T 0566-2005 in " highway engineering cement and cement concrete testing regulations " JTG E30-2005 Soil test specimen dry shrinkage testing, obtains the strain of concrete sample drying shrinkage.

Enter according to T 0855-2009 " instrument method " in " highway engineering stabilized with inorganic binder testing of materials code " JTG E51-2009 The contracting test of row cement concrete test specimen temperature, obtains concrete sample temperature contracting coefficient.

Prepare the continuous reinforcement concrete sample that expansive agent dosage is 0%, 8%, 10%, 12% respectively, used former in this embodiment Material is:

Extender: the 130 type HCSA high-performance cement expansive agents that District, Xinyang Area, Henan Province Bo Ou building materials company limited produces, refers specifically to Mark is as shown in table 1.

The performance indications of table 1HCSA extender

Cement: the PO 42.5 type cement that Qinling Mountains in Shaanxi cement limited company produces, performance indications meet " common Portland water Mud " (GB175-2007) requirement；

Fine aggregate: fluvial sand, this sand is medium sand, and technical specification meets " highway cement concrete pavement construction technique normalizing " (JTG F30-2003) technology requirement；

Coarse aggregate: granite stones, uses 5～10mm and the combination grating of 10～20mm two kind of particle diameter, and wherein 5～10mm Rubble quality: 10～20mm rubble quality=3:7.Technical specification meets " highway cement concrete pavement construction technique normalizing " (JTG F30-2003) technology requirement；

Flyash: I grade of flyash that Lingshou County, Hebei Sheng Yao mineral products company limited produces, its specific targets are as shown in table 2.

Table 2 flyash performance indications

Silicon ash: the silicon ash that Lingshou County, Hebei Sheng Yao mineral products company limited produces, its specific targets are as shown in table 3.

The index of table 3 silicon ash

Micro-polyvinyl alcohol (PVA) fiber: the PVA fiber that Taian Shandong Ling Zhong composite company limited produces, specific targets are such as Shown in table 4.

Table 4PVA fibrous material parameter

Micro-steel fibre: micro-steel fibre that Taian Shandong Ling Zhong composite company limited produces, specific targets are as shown in table 5.

Table 5 micro-steel fiber material parameter

Water reducer: the high efficiency water reducing agent of Shaanxi Zhong Yi Chemical Co., Ltd., pale yellow powder, water-reducing rate is up to 30%, can with appoint What ratio water is miscible, and volume selects the 1% of Binder Materials gross mass.Specific performance index is as shown in table 6.

The performance indications of table 6 water reducer

The water of mix is the drinking water in Xi'an, meets code requirement.

The cement concrete test specimen composition of this embodiment is as follows:

Test specimen is the prism of 10cm × 10cm × 40cm.Binder Materials quality is 1.76kg；Wherein: cement 1.27744kg, Flyash 0.3524kg, silicon ash 0.13216kg.Other material: water 0.74kg；Micro-steel fibre 0.1884kg；PVA fiber 0.004kg； Water reducer 0.0176kg；Sand 2.27136kg；Coarse aggregate 4.82664kg；Expansive agent dosage selects the 0% of Binder Materials quality respectively (0kg), 8% (0.1408kg), 10% (0.176kg) and 12% (0.2112kg).

Carry out drying shrinkage, temperature contracting test, it is thus achieved that drying shrinkage strain, temperature contracting coefficient.

Coagulating cement is carried out according to T 0566-2005 in " highway engineering cement and cement concrete testing regulations " JTG E30-2005 Soil test specimen dry shrinkage testing, obtains the test specimen coefficient of shrinkage.Wherein: in drying shrinkage case curing temperature be 20 ± 2 DEG C, relative humidity be 60 scholars 5%.According to T 0855-2009 " instrument method " in " highway engineering stabilized with inorganic binder testing of materials code " JTG E51-2009 Carry out the contracting test of cement concrete test specimen temperature, obtain test specimen temperature contracting coefficient.Wherein: temperature contracting test temperature is in the range of 0 DEG C～40 DEG C Change, temperature interval uses 10 DEG C, each temperature spot constant temperature 3h.The results are shown in Table 7.

28d concrete dry shrinkage strain, temperature contracting coefficient under the different expansive agent dosage of table 7

Step 2, calculates the fracture width of continuous reinforcement concrete, stress under different expansive agent dosage: strained by drying shrinkage, temperature contracts system Number is brought formula (1) into and is calculated the fracture width of continuous reinforced concrete pavement, substitutes into formula (2) and calculates continuous reinforced concrete pavement Maximum stress, result of calculation is as shown in table 8.

${\mathrm{\μ}}_c=\frac{2({\mathrm{\α}}_c\mathrm{\Δ}T+{\mathrm{\ϵ}}_{sh})(b_2-b_1)}{b_1{r}_{3}cth\left(r_{3}L\right)-b_2{r}_{1}cth\left(r_{1}L\right)}---\left(1\right)$

${\mathrm{\σ}}_s{|}_{x=0}=E_c({\mathrm{\α}}_c\mathrm{\Δ}T+{\mathrm{\ϵ}}_{sh})\[\frac{b_2{r}_1\csc h\left(r_{1}L\right)-B_1{r}_3\csc h\left(r_{3}L\right)}{b_1{r}_3\csc h\left(r_{3}L\right)-b_2{r}_1\csc h\left(r_{1}L\right)}+1\]---\left(2\right)$

Wherein:

b₁=(a₁+a₂-r₁ ²)/a₁；

b₂=(a₁+a₂-r₃ ²)/a₁；

$a_1=\frac{{\mathrm{\πd}}_s{k}_s}{A_c{E}_c};$

$a_2=\frac{k_{c}b}{A_c{E}_c};$

$a_3=\frac{{\mathrm{\πd}}_s{k}_s}{A_s{E}_s};$

$r_1=\sqrt{\frac{1}{2}\[a_1+a_2+a_3+\sqrt{{(a_1+a_2+a_3)}^2-4a_2{a}_3}\]};$

r₂=-r₁；

$r_3=\sqrt{\frac{1}{2}\[a_1+a_2+a_3-\sqrt{{(a_1+a_2+a_3)}^2-4a_2{a}_3}\]};$

r₄=-r₃；

Wherein, μ c is continuous reinforced concrete pavement fracture width, and unit is mm；σ_{S | x=0}For continuous reinforced concrete pavement Big stress, unit is MPa；α_cFor coagulation soil temperature contracting coefficient, unit is 10^-6/℃；Δ T is that temperature declines, and unit is DEG C；ε_sh For concrete dry shrinkage strain, unit is 10^-6；E_cFor modulus of elasticity of concrete, unit is Pa；L is the half of fracture interval, single Position is m；As is the area of reinforcement, and unit is m²；Ds is bar diameter, and unit is m；Es is reinforcing bar elastic modelling quantity, and unit is Pa；B is longitudinal reinforcement spacing, and unit is m；k_sFor the bonding stiffness coefficient between reinforcing bar and concrete, unit is Pa/m；k_cFor Frictional resistance coefficient between basic unit and surface layer, unit is Pa/m；H is surface thickness, and unit is m；Ac is concrete area, single Position is m²。

Table 8 fracture width and stress calculating results

Step 3, draws expansive agent dosage and fracture width, the relation curve of stress: respectively with expansive agent dosage as abscissa, point Do not draw curve with fracture width and concrete stress for vertical coordinate, as shown in Figure 1 and Figure 2.

Step 4, determines the optimum mix amount of extender: for avoiding the destruction of arching upward of continuous reinforced concrete pavement, takes continuous reinforcement and mixes The maximum crushing stress value of solidifying soil surface is 3.22MPa.According to step 3) in curve linear relationship, when expansive agent dosage is 12%, mixed The fracture width of solidifying soil is zero, forms certain compressive stress at inside concrete simultaneously, and compressive stress is less than 3.22MPa.According to Result of the test can extender the optimum mix amount be 12% under this embodiment.

Claims (4)

1. a continuous reinforced concrete pavement expansive agent dosage determines method, it is characterised in that comprise the following steps:

Step one, the continuous reinforcement concrete sample under the different expansive agent dosage of preparation, measure and join continuously under different expansive agent dosage The strain of reinforced concrete drying shrinkage, temperature contracting coefficient；

Step 2, calculates the fracture width of continuous reinforced concrete pavement, stress under different expansive agent dosage；

Step 3, draws expansive agent dosage and fracture width, the relation curve of stress respectively；

Step 4, determines the optimum mix amount of extender according to relation curve.

A kind of continuous reinforced concrete pavement expansive agent dosage the most according to claim 1 determines method, it is characterised in that In described step one, drying shrinkage strain, the mensuration of temperature contracting coefficient are obtained by cement concrete drying shrinkage, temperature contracting test；Drying shrinkage In test in curing box curing temperature be 20 ± 2 DEG C, relative humidity be 60 ± 5%；In temperature contracting test test temperature at 0 DEG C～ Changing in the range of 40 DEG C, temperature interval uses 10 DEG C, each temperature spot constant temperature 3h.

A kind of continuous reinforced concrete pavement expansive agent dosage the most according to claim 1 determines method, it is characterised in that In described step 2, calculate the fracture width of continuous reinforced concrete pavement under different expansive agent dosage, stress method as follows:

According to the drying shrinkage of continuous reinforcement concrete, temperature contracting coefficient under different expansive agent dosages, formula (1) is utilized to calculate continuous reinforcement The fracture width of concrete road surface, utilize formula (2) calculate continuous reinforced concrete pavement maximum stress:

${\mathrm{\μ}}_c=\frac{2({\mathrm{\α}}_c\mathrm{\Δ}T+{\mathrm{\ϵ}}_{sh})(b_2-b_1)}{b_1{r}_{3}cth\left(r_{3}L\right)-b_2{r}_{1}cth\left(r_{1}L\right)}---\left(1\right)$

${\mathrm{\σ}}_s{|}_{x=0}=E_c({\mathrm{\α}}_c\mathrm{\Δ}T+{\mathrm{\ϵ}}_{sh})\[\frac{b_2{r}_1\csc h\left(r_{1}L\right)-B_1{r}_3\csc h\left(r_{3}L\right)}{b_1{r}_3\csc h\left(r_{3}L\right)-b_2{r}_1\csc h\left(r_{1}L\right)}+1\]---\left(2\right)$

Wherein:

b₁=(a₁+a₂-r₁ ²)/a₁；

b₂=(a₁+a₂-r₃ ²)/a₁；

$a_1=\frac{{\mathrm{\πd}}_s{k}_s}{A_c{E}_c};$

$a_2=\frac{k_{c}b}{A_c{E}_c};$

$a_3=\frac{{\mathrm{\πd}}_s{k}_s}{A_s{E}_s};$

$r_1=\sqrt{\frac{1}{2}\[a_1+a_2+a_3+\sqrt{{(a_1+a_2+a_3)}^2-4a_2{a}_3}\]};$

r₂=-r₁；

$r_3=\sqrt{\frac{1}{2}\[a_1+a_2+a_3-\sqrt{{(a_1+a_2+a_3)}^2-4a_2{a}_3}\]};$

r₄=-r₃；

Wherein, μ_cFor continuous reinforced concrete pavement fracture width, unit is mm；σ_{S | x=0}For continuous reinforced concrete pavement Big stress, unit is MPa；α_cFor coagulation soil temperature contracting coefficient, unit is 10^-6/℃；Δ T is that temperature declines, and unit is DEG C；ε_sh For concrete dry shrinkage strain, unit is 10^-6；E_cFor modulus of elasticity of concrete, unit is Pa；L is the half of fracture interval, single Position is m；As is the area of reinforcement, and unit is m²；Ds is bar diameter, and unit is m；Es is reinforcing bar elastic modelling quantity, and unit is Pa；B is longitudinal reinforcement spacing, and unit is m；k_sFor the bonding stiffness coefficient between reinforcing bar and concrete, unit is Pa/m；k_cFor Frictional resistance coefficient between basic unit and surface layer, unit is Pa/m；H is surface thickness, and unit is m；Ac is concrete area, single Position is m²。

A kind of continuous reinforced concrete pavement expansive agent dosage the most according to claim 1 determines method, it is characterised in that In described step 4, determine that the method for the optimum mix amount of extender is as follows:

For avoiding the destruction of arching upward of continuous reinforced concrete pavement, the maximum crushing stress value taking continuous reinforced concrete pavement is 3.22MPa, according to the relation curve in step 3, fracture width value is 0, value of compressive stress is less than expansion minimum during 3.22MPa Agent volume is the optimum mix amount.