Anti-stripping agent for asphalt mixture including refined slowly-cooled slag, method for preparing the same, asphalt mixture including the same and method for preparing the same

Patent metadata

Field	Value
Publication number	US-11365318-B2
Application number	US-201816209628-A
Country	US
Kind code	B2
Filing date	Dec 4, 2018
Priority date	Jul 13, 2018
Publication date	Jun 21, 2022
Grant date	Jun 21, 2022

Abstract

The present technology relates to an anti-stripping agent for an asphalt mixture, which includes a refined slowly-cooled slag obtained by processing slag, generated in ironmaking and steelmaking processes, using a specific method, and to a method for preparing the same, an asphalt mixture including the same, and a method for preparing the asphalt mixture. The refined slowly-cooled slag may include 55 to 65 mass % of CaO, 5 to 10 mass % of SiO2, 1 to 5 mass % of Al2O3, and 1 to 5 mass % of MgO.

First claim

What is claimed is:

1. An anti-stripping agent for an asphalt mixture comprising a refined iron and steel slag, wherein the refined iron and steel slag comprises 55 to 65 mass % of CaO, 5 to 10 mass % of SiO 2 , 1 to 5 mass % of Al 2 O 3 , and 1 to 5 mass % of MgO,
wherein the anti-stripping agent has a water content of from 0.4 to 0.6 wt % uniformly distributed throughout,
wherein the refined iron and steel slag is in the form of a powder of particles of less than 70 mm in diameter, and
wherein the anti-stripping agent exhibits plasticity index of 6 or less, flow index 50% or less, swelling 3% or less, and anti-stripping performance of ¼ or less.

2. The anti-stripping agent of claim 1 ,
wherein the refined iron and steel slag further comprises one or more selected from the group consisting of MnO, Na 2 O, K 2 O, P 2 O 5 and TiO 2 in an amount of 0.001 to 0.5 mass %.

3. The anti-stripping agent of claim 1 , wherein the refined iron and steel slag is obtained by processing iron and steel slag so as to remove any ferrous material and increase the collection and recovery of a nonferrous material comprising CaO, SiO 2 , Al 2 O 3 and MgO.

4. The anti-stripping agent of claim 1 ,
wherein the refined iron and steel slag further comprises MnO, Na 2 O, K 2 O, P 2 O 5 and TiO 2 each in an amount of 0.001 to 0.5 mass % and is substantially free of any ferrous material,
wherein the powder of particles has a particle distribution as follows:

Particle size
Sieve size
Quality standard (% passage)

 0.6 mm
100

 0.3 mm
95 or more

0.15 mm
90 or more

0.08 mm
70 or more

and
wherein the refined iron and steel slag precipitates a calcium ion on a surface of aggregate in the asphalt mixture, and the precipitated calcium ion binds to an acid contained in asphalt to form an insoluble salt, thereby improving adhesion between the asphalt and the aggregate.

5. An asphalt mixture comprising: an anti-stripping agent for an asphalt mixture according to claim 1 ; aggregate; and asphalt.

6. The asphalt mixture of claim 5 , wherein the anti-stripping agent is contained in an amount of 0.5 to 6.0 wt % based on the weight of the aggregate.

7. The asphalt mixture of claim 5 , wherein a weight ratio between the asphalt and the aggregate is in the range of 3.5:96.5 to 6.0:94.0.

Assignees

• Korea Inst Civil Eng & Building Tech
• Sp Nature Co Ltd

Inventors

• Kwon Soo Ahn
• Lee Moon Sup
• Lee Kang Hun
• Son Jeong Tan
• Han Young Nam
• Ha Dong Ho
• Jang Byoung In
• Lee Jin Hyoung

Classifications

• C08L95/005 Primary

  Aqueous compositions, e.g. emulsions · CPC title

• C04B18/141

  Slags · CPC title

• E01C7/26

  mixed with other materials, e.g. cement, rubber, leather, fibre {(fibrous material reinforcements for bituminous paving E01C11/165)} · CPC title

• C04B26/26

  Bituminous materials, e.g. tar, pitch {(C08L95/00 takes precedence)} · CPC title

• C04B18/142 Primary

  Steelmaking slags, converter slags · CPC title