Paving compositions and methods of making same

Claim 2

IN A METHOD OF MAKING AN ASPHALT PAVEMENT IN WHICH HOT ASPHALT IS MIXED WITH A MINERAL AGGREGATE TO PROVIDE A PAVING COMPOSITION THAT IS FORMED INTO PAVEMENT RELATIVELY SOON AFTER MIXING, THE IMPROVEMENT COMPRISING THE STEPS OF:

Claim 3

MIXING (1) ABOUT 4 TO 10% BY WEIGHT OF THE PAVING COMPOSITION OF HOT ASPHALT HAVING A PENETRATION OF ABOUT 60 TO 90 WITH (2) A FINELY DIVIDED MINERAL AGGREGATE HAVING A MESH SIZE OF ABOUT 4 TO 200 MESH IN WHICH EACH PARTICLE HAS A SIZE NOT SUBSTANTIALLY LARGER THAN ABOUT ONE-SIXTEENTH INCH, THE AGGREGATE INCLUDING (A) PARTICLES OF UNCOATED SAND AND (B) ABOUT 2 TO 60%, BY WEIGHT, OF THE COMPOSITION OF PARTICLES OF SAND COATED WITH AN OILSOLUBLE CURABLE THERMOPLASTIC RESIN THAT IS COMPATIBLE WITH THE ASPHALT AND (3) SUFFICIENT AMOUNT OF A HARDENING AGENT FOR CURING THE RESIN WHEN CONTACTED WITH THE HOT ASPHALT, AND

Claim 4

MIXING (1) ABOUT 4 TO 10% BY WEIGHT OF THE PAVING COMPOSITION OF HOT ASPHALT HAVING A PENETRATION OF ABOUT 60 TO 90 WITH (2) A FINELY DIVIDED MINERAL AGGREGATE HAVING A MESH SIZE OF ABOUT 4 TO 200 MESH IN WHICH EACH PARTICLE HAS A SIZE NOT SUBSTANTIALLY LARGER THAN ABOUT ONE-SIXTEENTH INCH, THE AGGREGATE INCLUDING (A) PARTICLES OF UNCOATED SAND AND (B) ABOUT 2 TO 60%, BY WEIGHT, OF THE COMPOSITION OF PARTICLES OF SAND COATED WITH AN OILSOLUBLE CURABLE THERMOPLASTIC RESIN THAT IS COMPATIBLE WITH THE ASPHALT AND (3) SUFFICIENT AMOUNT OF A HARDENING AGENT FOR CURING THE RESIN WHEN CONTACTED WITH THE HOT ASPHALT, AND

Claim 5

FORMING THE MIXTURE OF STEP (1) AND HARDENING THE SAME INTO ASPHALT PAVEMENT HAVING HIGH STABILITY AND GOOD FLOW PROPERTIES, THE PAVEMENT HAVING STABILITY OF AT LEAST ABOUT 1,200 POUNDS BY THE MARSHALL STABILITY TEST AND A FLOW OF ABOUT 7 TO 15 AS MEASURED BY THE INCLINED GLASS PLATE FLOW TEST IN WHICH MILLIMETERS OF FLOW OF A 0.5 GRAM TABLET OF THE RESIN HEATED TO 125*C ARE RECORDED WHEN THE PLATE IS INCLUDED 65* FROM THE HORIZONTAL.

Claim 6

FORMING THE MIXTURE OF STEP (1) AND HARDENING THE SAME INTO ASPHALT PAVEMENT HAVING HIGH STABILITY AND GOOD FLOW PROPERTIES, THE PAVEMENT HAVING STABILITY OF AT LEAST ABOUT 1,200 POUNDS BY THE MARSHALL STABILITY TEST AND A FLOW OF ABOUT 7 TO 15 AS MEASURED BY THE INCLINED GLASS PLATE FLOW TEST IN WHICH MILLIMETERS OF FLOW OF A 0.5 GRAM TABLET OF THE RESIN HEATED TO 125*C ARE RECORDED WHEN THE PLATE IS INCLUDED 65* FROM THE HORIZONTAL.

Claim 7

forming the mixture of step (1) and hardening the same into asphalt pavement having high stability and good flow properties, the pavement having a stability of at least about 1,200 pounds by the Marshall stability test and a flow of about 7 to 15 as measured by the inclined glass plate flow test in which millimeters of flow of a 0.5 gram tablet of the resin heated to 125*C are recorded when the plate is inclined 65* from the horizontal.

Claim 8

forming the mixture of step (1) and hardening the same into asphalt pavement having high stability and good flow properties, the pavement having a stability of at least about 1,200 pounds by the Marshall stability test and a flow of about 7 to 15 as measured by the inclined glass plate flow test in which millimeters of flow of a 0.5 gram tablet of the resin heated to 125*C are recorded when the plate is inclined 65* from the horizontal.

Claim 9

A method as defined in claim 1 in which the resin is an oil-soluble thermoplastic phenol-formaldehyde novolak resin.

Claim 10

A method as defined in claim 2 in which the mineral aggregate includes limestone dust in an amount of about 4 to 14%, by weight, of the paving composition, the total amount of coated and uncoated sand is about 70 to 90%, by weight, of the composition, and the novolak resin is a normally solid acid-catalyzed reaction product of about 0.75 to 0.9 moles of formaldehyde per mole of phenol.

Claim 11

In a method of making asphalt pavement in which asphalt is mixed with heated mineral aggregate to form a mineral aggregate/asphalt composition that is subsequently mixed with hot asphalt at the paving site to provide a paving composition that is formed into pavement relatively soon after mixing, the improvement which comprises the step of mixing a plurality of sand particles with a coating composition comprising (1) about 70 to 90 parts, by weight, of an oil-soluble phenol-formaldehyde novolak resin that adheres to the sand particle and is compatible with the asphalt (2) about 20 to 40 parts, by weight, of hot asphalt and (2) (3) a sufficient amount of a hardening agent comprising hexamethylene tetramine to convert the resin to a thermoset resin when mixed with the hot asphalt to provide thereby the mineral aggregate/asphalt composition that, when mixed with the asphalt, provides a pavement having high stability and good flow properties, the resultant pavement having a stability of at least 1500 pounds by the Marshall stability test.

Claim 12

In a method of making asphalt pavement in which asphalt is mixed with heated mineral aggregate to form a mineral aggregate/asphalt composition that is subsequently mixed with hot asphalt at the paving site to provide a paving composition that is formed into pavement relatively soon after mixing, the improvement which comprises the step of mixing a plurality of sand particles with a coating composition comprising (1) about 70 to 90 parts, by weight, of an oil-soluble phenol-formaldehyde novolak resin that adheres to the sand particle and is compatible with the asphalt (2) about 20 to 40 parts, by weight, of hot asphalt and (2) (3) a sufficient amount of a hardening agent comprising hexamethylene tetramine to convert the resin to a thermoset resin when mixed with the hot asphalt to provide thereby the mineral aggregate/asphalt composition that, when mixed with the asphalt, provides a pavement having high stability and good flow properties, the resultant pavement having a stability of at least 1500 pounds by the Marshall stability test.

Claim 13

A method as defined in claim 4 in which the asphalt pavement is formed from the following composition:

Claim 14

A method as defined in claim 4 in which the mineral aggregate is limestone dust and sand, the asphalt and uncoated mineral aggregate are hot enough to heat the resin and the hardening agent of the coating composition to a curing temperature of about 450*F for at least about 3 seconds, the coated sand being at least about 5% by weight of the total aggregate, and the coating composition comprises about 70 to 90 parts by weight of the novolak resin, about 10 to 30 parts of the asphalt, about 5 to 15 parts hexamethylene tetramine, and about 2 to 10 parts of wax as a lubricant.

Claim 15

An asphalt composition for forming into pavement having good durability, skid resistance, smoothness, high stability and good flow, the composition comprising: a. about 8.5 parts, by weight, of asphalt having a penetration of about 60 to 90, b. about 12 parts, by weight, of a mineral aggregate comprising limestone dust, and c. about 79.5 parts, by weight, of a plurality of finely divided particles of sand, about 10%, by weight, of the particles being coated with a coating composition comprising an oil soluble thermosettable phenol-formaldehyde resin compatible with the asphalt, and sufficient hardening agent to cure the resin to provide the pavement having a stability of at least about 1500 pounds measured by the Marshall stability test and a flow of about 7 to 15 as measured by the inclined glass plate flow test in which the millimeters of flow of a 0.5 grams tablet of the resin heated to 125*C are recorded when the plate is inclined at 65* from the horizontal.

Claim 16

An asphalt composition for forming into pavement having good durability, skid resistance, smoothness, high stability and good flow, the composition comprising: a. about 8.5 parts, by weight, of asphalt having a penetration of about 60 to 90, b. about 12 parts, by weight, of a mineral aggregate comprising limestone dust, and c. about 79.5 parts, by weight, of a plurality of finely divided particles of sand, about 10%, by weight, of the particles being coated with a coating composition comprising an oil soluble thermosettable phenol-formaldehyde resin compatible with the asphalt, and sufficient hardening agent to cure the resin to provide the pavement having a stability of at least about 1500 pounds measured by the Marshall stability test and a flow of about 7 to 15 as measured by the inclined glass plate flow test in which the millimeters of flow of a 0.5 grams tablet of the resin heated to 125*C are recorded when the plate is inclined at 65* from the horizontal.

Claim 17

A composition as defined in claim 1 in which the mineral aggregate includes limestone dust and sand, and the oil soluble resin is a phenol-formaldehyde novolak resin that is the acid-catalyzed reaction product of about 0.75 to 0.9 moles of formaldehyde per mole of phenol.

Claim 18

A composition as defined in claim 7 in which the asphalt has a penetration with a range of 70 to 85 and the resin is a phenol-formaldehyde novolak resin that is the acid-catalyzed reaction product of about 0.75 to 0.9 moles of formaldehyde per mole of phenol.

Claim 19

A sand/asphalt pavement having high stability and flow containing a bituminous binder and a mineral aggregate having a mesh size of about 4 to 200 mesh in which each particle has a size not substantially larger than about one-sixteenth inch, the aggregate including uncoated sand particles and about 2 to 60%, by weight, of the pavement being particles of coated sand, each sand particle being coated with a coating composition comprising an oil soluble thermoplastic resin compatible with the bituminous binder and sufficient hardening agent to convert the resin to a thermoset resin when mixed with the hot bituminous binder, the pavement having a stability of at least about 1,200 pounds as measured by the Marshall stability test and a flow of about 7 to 15.

Claim 20

A sand/asphalt pavement having high stability and flow containing a bituminous binder and a mineral aggregate having a mesh size of about 4 to 200 mesh in which each particle has a size not substantially larger than about one-sixteenth inch, the aggregate including uncoated sand particles and about 2 to 60%, by weight, of the pavement being particles of coated sand, each sand particle being coated with a coating composition comprising an oil soluble thermoplastic resin compatible with the bituminous binder and sufficient hardening agent to convert the resin to a thermoset resin when mixed with the hot bituminous binder, the pavement having a stability of at least about 1,200 pounds as measured by the Marshall stability test and a flow of about 7 to 15.

Claim 21

A pavement as defined in claim 10 in which the oil soluble resin is a phenol-formaldehyde novolak resin and the hardening agent is hexamethylene tetramine.

Claim 22

A pavement as defined in claim 11 in which the bituminous binder is an asphalt having a penetrAtion of about 60 to 90 and comprises about 8.5% by weight of the pavement, the mineral aggregate is a mixture of limestone dust in an amount of about 12% by weight of the pavement, the total sand is about 79% by weight of the pavement, and the coated sand is about 10% by weight of the total sand.

Claim 23

A pavement as defined in claim 12 in which the novolak resin is an acid-catalyzed reaction product of about 0.75 to 0.9 moles of formaldehyde per mole of phenol.

Claim 24

A pavement as defined in claim 13 in which the hexamethylene tetramine is about 15% by weight of the novolak resin and the coating composition contains wax as a lubricant.

Claim 25

An asphalt composition for forming into pavement having good durability, skid resistance, smoothness, high stability and good flow, the composition comprising: a. about 4 to 10%, by weight, or the composition of asphalt having a penetration within a range of 40 to 130, and a mineral aggregate having a mesh size of about 4 to 200 in which each particle has a size not substantially larger than about one-sixteenth inch, the aggregate including (A) particles of uncoated sand and (B) about 2 to 60%, by weight, of the composition of particles of sand coated with a coating composition comprising an oil soluble thermosetting resin, compatible with the asphalt, and (C) sufficient hardening agent to cure the resin to provide the pavement having a stability of at least about 1,200 pounds measured by the Marshall stability test and a flow of about 7 to 15 as measured by the inclined glass plate flow test in which the millimeters of flow of a 0.5 grams tablet of the resin heated to 125* are recorded when the plate is inclined at 65* from the horizontal.

Claim 26

An asphalt composition for forming into pavement having good durability, skid resistance, smoothness, high stability and good flow, the composition comprising: a. about 4 to 10%, by weight, or the composition of asphalt having a penetration within a range of 40 to 130, and a mineral aggregate having a mesh size of about 4 to 200 in which each particle has a size not substantially larger than about one-sixteenth inch, the aggregate including (A) particles of uncoated sand and (B) about 2 to 60%, by weight, of the composition of particles of sand coated with a coating composition comprising an oil soluble thermosetting resin, compatible with the asphalt, and (C) sufficient hardening agent to cure the resin to provide the pavement having a stability of at least about 1,200 pounds measured by the Marshall stability test and a flow of about 7 to 15 as measured by the inclined glass plate flow test in which the millimeters of flow of a 0.5 grams tablet of the resin heated to 125* are recorded when the plate is inclined at 65* from the horizontal.

Claim 27

A composition as defined in claim 15 and in which the mineral aggregate includes limestone dust used as a filler material.

Claim 28

A composition as claimed in claim 15, whereby the asphalt and uncoated mineral aggregate are hot enough and mixed sufficiently together to heat the resin and hardening agent of the coated aggregate to a curing temperature of at least about 400*F that is sufficient to provide the pavement with a stability of at least 1200 pounds measured by the Marshall stability test and a flow of about 7 to 15 as measured by the inclined glass plate flow test in which the millimeters of flow of a 0.5 grams tablet of the resin heated to 125*C are recorded when the plate is inclined at 65* from the horizontal.