Latex cement mortar poured anti-rutting pavement structure and paving method thereof

Abstract

An anti-rutting pavement structure is arranged consecutively from bottom to top, a semi-rigid base layer, a SBS emulsified asphalt adhesive layer, a Type II latex cement mortar poured asphalt concrete lower layer, a Type I latex cement mortar poured asphalt concrete middle layer and a high viscosity modified asphalt SMA-13 concrete surface layer.

Claims

1. An anti-rutting pavement structure, characterized in that it comprises, arranged consecutively from bottom to top, a semi-rigid base layer (1), a SBS emulsified asphalt adhesive layer (2), a Type II latex cement mortar poured asphalt concrete lower layer (3), a Type I latex cement mortar poured asphalt concrete middle layer (4) and a high viscosity modified asphalt SMA-13 concrete surface layer (5); the Type II latex cement mortar poured asphalt concrete lower layer (3) is composed of a macropore open-graded asphalt mixture and a latex cement mortar; wherein the mass ratio of the macropore open-graded asphalt mixture and the latex cement mortar is 57:1; the porosity of the macropore open-graded asphalt mixture is 2535%, and it is formed by mixing an asphalt mixture with an aggregate smaller than 19 mm in a mass ratio of 48: 100; the latex cement mortar is formed by mixing a latex modifier, cement, standard sand and water in a mass ratio of 7:100:25:65; wherein the latex cement mortar is impregnated into the macropore open-graded asphalt mixture through the pores of the macropore-opened asphalt mixture; the Type I latex cement mortar poured asphalt concrete middle layer (4) is composed of a macropore open-graded asphalt mixture and a latex cement mortar; wherein the mass ratio of the macropore open-graded asphalt mixture and the latex cement mortar is 57:1; the porosity of the macropore open-graded asphalt mixture is 2535%, and it is formed by mixing an asphalt mixture with an aggregate smaller than 16 mm in a mass ratio of 48: 100; the latex cement mortar is formed by mixing a latex modifier, cement, standard sand and water in a mass ratio of 6:100:20:60; wherein the latex cement mortar is impregnated into the macropore open-graded asphalt mixture through the pores of the macropore-opened asphalt mixture; the high viscosity modified asphalt SMA-13 concrete surface layer (5) is formed by mixing a high viscosity modified asphalt binder with an aggregate in a mass ratio of 5.56.5: 100; wherein the high viscosity modified asphalt binder is composed of a Styrene-butadiene-styrene copolymer modified asphalt, a thermoplastic rubber, a bonding resin and a plasticizer, in a mass ratio of 100: 10: 2: 1.

2. The anti-rutting pavement structure according to claim 1, characterized in that the spraying amount per unit area of the SBS emulsified asphalt adhesive layer (2) is 0.50.8kg/m.sup.2.

3. The anti-rutting pavement structure according to claim 1, characterized in that the Type II latex cement mortar poured asphalt concrete lower layer (3) has a thickness of 78 cm.

4. The anti-rutting pavement structure according to claim 1, characterized in that the Type I latex cement mortar poured asphalt concrete middle layer (4) has a thickness of 56 cm.

5. The anti-rutting pavement structure according to claim 1, characterized in that the high viscosity modified asphalt SMA-13 concrete surface layer (5) has a thickness of 4 cm.

6. The anti-rutting pavement structure according to claim 1, characterized in that the latex modifier is an acrylic ester copolymer.

7. A method of paving for an anti-rutting pavement structure according to claim 1, characterized in that it is formed by laying consecutively the SBS emulsified asphalt adhesive layer (2), the Type II latex cement mortar poured asphalt concrete lower layer (3) of 78 cm, the Type I latex cement mortar poured asphalt concrete middle layer (4) of 56 cm and the high viscosity modified asphalt SMA-13 concrete surface layer (5) of 4 cm onto the semi-rigid base layer (1).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a structure schematic diagram of the invention.

DETAILED DESCRIPTION

(2) The embodiments of the present invention consider that (1) the main shear force of the pavement structure under the condition of semi-rigid base layer increases first and then decreases with the increasing depth under the driving load, and the peek value occurs in the middle, lower layer of pavement. The insufficient shear resistance of the middle, lower layer of pavement under high temperature may cause an irreversible accumulation of plastic deformation under vehicle load, forming pavement rutting distress; (2) regarding that the pavement surface layer needs to meet more of structural requirement than functional requirement, i.e. the cracks in the pavement are as little as possible and shrinkage and expansion joints needs not to be arranged, meanwhile meeting the requirement of crack-resistance under lower temperature and ensuring comfort and safety of the vehicle driving to the utmost; (3) regarding that the pavement structure has a general thickness of 1820 cm, normally the thickness of the middle layer is 56 cm and that of the lower layer is 78 cm. Standard Specification for Construction and Acceptance of Highway Asphalt Pavement (JTGF40-2004) shows that for hot mixing paste asphalt mixture, the compressed thickness of one asphalt layer should not be smaller than 2.53 times maximum nominal particle size of the aggregate. Meanwhile according to the relative regulation of the minimum compactness and suitable thickness for the asphalt mixture structural layer in Table 4.1.3 of Standard Specification for Construction and Acceptance of Highway Asphalt Pavement (JTGD50-2006), the maximum normal particle size of the Type II latex cement mortar poured asphalt concrete is 19 mm, and its suitable thickness is 6080 mm, therefore it can only be used in the lower layer instead of the upper layer of 40 mm and middle layer of 50 mm, otherwise the structure doesn't meet the design specifications. The maximum normal particle size of the Type I latex cement mortar poured asphalt concrete is 16 mm, and its suitable thickness is 4060 mm, therefore it can only be used in the middle or upper layer instead of lower of 80 mm, otherwise the structure doesn't meet the design specifications.

(3) Based on above considerations, the Embodiment 1 of the present invention provides a paving method for anti-rutting pavement structure, which meets above factors in terms of the following angles: (1) the lower layer in the pavement structure utilizes the latex cement mortar poured asphalt mixture which resists rutting, meeting the structural requirements of pavement; (2) the surface layer utilizes the high viscosity modified asphalt SMA-13 concrete, meeting the functional requirements of pavement; (3) the middle layer of pavement utilizes the Type I latex cement mortar poured asphalt concrete, of which the aggregate has a maximum normal particle size of 16 mm, and the lower layer utilizes the Type II latex cement mortar poured asphalt concrete, of which the aggregate has a maximum normal particle size of 19 mm. This scheme is embodied specifically as in FIG. 1.

(4) At the same time, Example 2 of the present invention compares different pavement structures with the semi-rigid base layer to compare the crack resistance and tensile and performance of resisting rutting of each pavement structure.

(5) In the following embodiments,

(6) The utilized latex modifier is ZBR-608 emulsion produced from Zhengbang Chemical, Co., Ltd, Yunnan.

(7) The utilized thermoplastic rubber is styrene-butadiene-styrene block copolymer;

(8) The utilized adhesive resin is polyethylene;

(9) The utilized plasticizer is dioctyl phthalate.

(10) Embodiment 1

(11) As shown in FIG. 1, the anti-rutting pavement structure is arranged consecutively from bottom to top with the semi-rigid base layer, the SBS emulsified asphalt adhesive layer, the Type II latex cement mortar poured asphalt concrete layer, the Type I latex cement mortar poured asphalt concrete layer and the high viscosity modified asphalt SMA-13 concrete layer.

(12) Wherein the spraying amount of the semi-rigid base layer and the SBS emulsified asphalt adhesive layer is 0.6 kg/m.sup.2, the Type II latex cement mortar poured asphalt concrete layer has a thickness of 8 cm, the Type I latex cement mortar poured asphalt concrete layer has a thickness of 5 cm, the high viscosity modified asphalt SMA-13 concrete layer has a thickness of 4 cm.

(13) The Type II latex cement mortar poured asphalt concrete material layer is composed of a macropore open-graded asphalt mixture and a latex cement mortar in a mass ratio of 6:1; wherein the macropore open-graded asphalt mixture is formed by mixing a asphalt mixture with an aggregate smaller than 19 mm in a mass ratio of 5:100, and the porosity of the macropore open-graded asphalt mixture is 30%; the latex cement mortar is composed of a latex modifier, cement, standard sand and water in a mixing ratio of 7:100:25:65; the latex cement mortar is impregnated into the macropore open-graded asphalt mixture through the pores with the porosity of 30% of the macropore-opened asphalt mixture.

(14) The Type I latex cement mortar poured asphalt concrete material layer is composed of a macropore open-graded asphalt mixture and a latex cement mortar in a mass ratio of 6:1; wherein the macropore open-graded asphalt mixture is formed by mixing a asphalt mixture with an aggregate smaller than 16 mm in a mass ratio of 6:100, and the porosity of the macropore open-graded asphalt mixture is 25%; the latex cement mortar is composed of a latex modifier, cement, standard sand and water in a mixing ratio of 6:100:20:60; the latex cement mortar is impregnated into the macropore open-graded asphalt mixture through the pores with the porosity of 25% of the macropore-opened asphalt mixture;

(15) The high viscosity modified asphalt SMA-13 concrete is mixed by a bonding material with an aggregate in a mass ratio of 6.0:100; wherein the high viscosity modified asphalt binder is composed of a Styrene-butadiene-styrene copolymer modified asphalt, a thermoplastic rubber, a bonding resin and a plasticizer, in a mixing ratio of 100:10:2:1;

(16) In the anti-rutting pavement paving structure of the present embodiment, each technical index meets the structural requirements for use, the test results are specially shown in Table 6 as below:

(17) TABLE-US-00006 TABLE 6 Test results technical No. Item index test value requirement 1 Marshall 40.6 kN (Type I latex cement 30 kN strength mortar poured asphalt concrete) 52.3 kN (Type II latex cement mortar poured asphalt concrete) 2 dynamic 21540 times/mm 6000 times/mm stability (70 C., composite structure *) 3 low 5.2 10.sup.3 (15 C., 3.0 10.sup.3 temperature composite structure) bending strain

(18) Among them, the composite structure: the test specimen used in the process is a structural form of high viscosity modified asphalt SMA-13 concrete+Type I latex cement mortar poured asphalt concrete+Type II latex cement mortar poured asphalt concrete based an equal thickness proportion with the anti-rutting pavement paving structure of the present invention.

(19) Embodiment 2

(20) In this comparative example, the pavement structure is arranged consecutively from bottom to top with the semi-rigid base layer, SBS emulsified asphalt adhesive layer, lower layer, middle layer, surface layer.

(21) Wherein the spraying amount of the semi-rigid base layer and the SBS emulsified asphalt adhesive layer is 0.6 kg/m.sup.2, the lower layer has a thickness of 8 cm, the middle layer has a thickness of 5 cm, the surface layer has a thickness of 4 cm.

(22) According to the relative regulation of the minimum compactness and suitable thickness for the asphalt mixture structural layer in Table 4.1.3 of Standard Specification for Construction and Acceptance of Highway Asphalt Pavement (JTGD50-2006), the maximum normal particle size of the Type II latex cement mortar poured asphalt concrete is 19 mm, and its suitable thickness is 6080 mm, therefore it can only be used in the lower layer instead of the upper layer of 40 mm and middle layer of 50 mm, otherwise the structure doesn't meet the design specifications. The maximum normal particle size of the Type I latex cement mortar poured asphalt concrete is 16 mm, and its suitable thickness is 40-60 mm, therefore it can only be used in the middle or upper layer instead of lower of 80 mm, or otherwise the structure doesn't meet the design specifications. According to the relationship between the maximum normal particle size and suitable pavement thickness of above mixture, the comparative example includes:

(23) Structure 1 of high viscosity modified asphalt SMA-13 concrete surface layer+Type I latex cement mortar poured asphalt concrete middle layer+Type II latex cement mortar poured asphalt concrete lower layer.

(24) Structure 2 of Type I latex cement mortar poured asphalt concrete upper layer+Type I latex cement mortar poured asphalt concrete middle layer+Type II latex cement mortar poured asphalt concrete lower layer.

(25) Wherein the Type II latex cement mortar poured asphalt concrete material layer is composed of a macropore open-graded asphalt mixture and a latex cement mortar in a mass ratio of 6:1; wherein the macropore open-graded asphalt mixture is formed by mixing an asphalt mixture with an aggregate smaller than 19 mm in a mass ratio of 5:100, and the porosity of the macropore open-graded asphalt mixture is 30%; the latex cement mortar is composed of a latex modifier, cement, standard sand and water; the latex cement mortar is impregnated into the macropore open-graded asphalt mixture through the pores with the porosity of 30% of the macropore-opened asphalt mixture.

(26) The Type I latex cement mortar poured asphalt concrete material layer is composed of a macropore open-graded asphalt mixture and a latex cement mortar in a mass ratio of 6:1; wherein the macropore open-graded asphalt mixture is formed by mixing a asphalt mixture with an aggregate smaller than 16 mm in a mass ratio of 6:100, and the porosity of the macropore open-graded asphalt mixture is 25%; the latex cement mortar is composed of a latex modifier, cement, standard sand and water in a mixing ratio of 6:100:20:60; the latex cement mortar is impregnated into the macropore open-graded asphalt mixture through the pores with the porosity of 25% of the macropore-opened asphalt mixture;

(27) The high viscosity modified asphalt SMA-13 concrete is mixed by a bonding material with an aggregate in a mass ratio of 6.0:100; wherein the high viscosity modified asphalt binder is composed of a Styrene-butadiene-styrene copolymer modified asphalt, a thermoplastic rubber, a bonding resin and a plasticizer, in a mixing ratio of 100:10:2:1;

(28) In the anti-rutting pavement paving structure of the present embodiment, each technical index meets the structural requirements for use, the results of comparative test are specially shown in Table 7 as below:

(29) TABLE-US-00007 TABLE 7 Results of comparative test dynamic low temperature pavement structure stability bending strain Structure 1 (SMA + I + II) 21540 5.2 10.sup.3 Structure 2 (I + I + II) 23452 1.9 10.sup.3 (does not meet the technical requirement) technical requirement 6000 times/mm 3.0 10.sup.3

(30) It can be seen from the specific implementation provided by above embodiments of the present invention that the new paving process employed by the embodiments of the present invention takes both the structural and functional requirement for the pavement into account. Under the condition of semi-rigid base layer, the latex cement mortar poured asphalt concrete employed by the middle, lower layer can resist effectively the formation of rutting, and the high viscosity modified asphalt SMA-13 concrete ensures effectively the pavement resistance to tensile and cracking. At the same time, the joint utilization of Type I and Type II latex cement mortar poured asphalt concrete materials can be suitable for the requirement for the maximum normal particle size of the road with different layer thickness, can allow the pavement to have a better compactness, thereby enhancing the high temperature stability, low temperature crack-resistance and usability, and so it has a larger application prospect for newly-built roads and reconstructed and expanded roads.