ANALYSIS OF MECHANICAL PROPERTIES OF ASPHALT MIX …

Tianjin DaxueXuebao (ZiranKexueyuGongchengJishu Ban)/ Journal of Tianjin University Science and Technology ISSN (Online): 0493-2137 E-Publication: Online Open Access Vol:54 Issue:08:2021 DOI 10.17605/OSF.IO/2ZYVK

August 2021 | 126

ANALYSIS OF MECHANICAL PROPERTIES OF ASPHALT MIX

USING LAHAR SAND AND CRUMB RUBBER TIRE AS

REPLACEMENT FOR FINE AGGREGATES

Dr. Manuel M. Muhi Polytechnic University of the Philippines [email protected]

Engr. Kenneth Bryan M. Tana Polytechnic University of the Philippines [email protected]

Abstract-Many alternatives are used in construction industry nowadays. One of which is utilizing waste material as an additive or a replacement to materials used in construction. Materials having excessive amount such as lahar sand from eruption of Mount Pinatubo and rubber tire disposal are considered as waste products. Utilization of the said materials is the purpose of this study. Subsequent to this, the mechanical properties of lahar sand and crumb rubber tire which will be partially replaced to fine aggregates for the asphalt mixture’s optimum design was deliberated. The physical properties of the materials were also determined. The mixture must satisfy the American Society for Testing and Materials (ASTM) Asphalt Mixture Standard and Marshall Stability Criteria. The mix design used was a fixed amount of 5.07 percent of Asphalt binder and varying amounts of lahar sand ranging from ten to fifty percent with interval of ten and crumb rubber tire with one, three, and five percent content. The results showed that the more lahar sand is used in the mixture, the higher its stability. On the contrary, as the crumb rubber tire increases, the lower the stability of the mixture obtained. The implication of these results is that varying amount of lahar sand and crumb rubber tire greatly affect the values of Marshall Properties. Thus, with optimum mixture, this alternative can contribute in diminishing the excessive amount of waste materials in the country.

Keywords – lahar sand, crumb rubber tire, mechanical properties, asphalt, fine aggregates

1. INTRODUCTION

The rubber tires that were invented in 17th century made a great impact in travelling using cars and bicycles. With the comfort it provides, the world embraces the use of rubber tires and needs lot of production to meet its demand. In over 400 tire factories worldwide, 1 billion units of tires has been produced. World demand for tires is projected to rise 4.1 percent annually to 3.0 billion units in 2019. Motor vehicles remain the dominant tire market, while motorcycles and other applications will grow the fastest. The Asia Pacific region will remain the largest tire market (Freedonia Group, 2015).

mailto:[email protected]


August 2021 | 127

Aging of tire is usually the problem faced by car owners. An old tire develops issues such as separation of treads due to pressure, heat exposure and other factors affecting the quality of the tire. Thus leading to accidents. Aging process starts to occur the moment your tire is installed in your vehicle. The average mileage of a tire ranges from 6000 miles up to 12000 miles. The Saudi Arabia study showed that a tire used on a vehicle for one year had equivalent aging to a tire in storage for 10 years. A one-year old used tire can also be dangerous if not maintained properly. It took 20 years in storage at 40 degrees Celsius for the tire to age the same as a tire used at 40,000 km. (Nunag, 2017). This shows that a tire used has a shorter life than the ones stored.

It is estimated that 13.5 million tons of tires are scrapped every year and a lot of those end up in landfills. Unrecycled tire waste is an enormous global problem because of their non-biodegradability and present a lot of environmental issues and health risks. They can be a breeding ground for mosquitoes which carry different diseases like dengue, malaria and encephalitis. Tires are flammable and they produce a toxic smoke that is harmful to the humans and the environment. They are hard to extinguish and can burn for several weeks.

Since the Pinatubo volcanic eruption in 1991, lahar sand has been a major problem in areas of Central Luzon. Thick lahar deposits have flooded the 39 towns and 4 large cities and affected more than 1,350,000 people and over a thousand kilometers of prime agricultural land. (Janda, 1999).

The excess amount of lahar sand from the eruption has caused severe siltation of rivers, and blocking of waterways resulting in severe flooding. (Sapnu, 2011) Most lahar from Pinatubo begin as surface runoff of rainfall. Intense rainfall easily erodes loose sediment on steep slopes to produce lahars that travel onto flood plains and bury entire towns, agricultural lands and properties. Whenever it rains, lahar would flow down from the mountains clogging the channels and passages of flowing water. These lahars can wreak havoc and may produce chronic flooding.

Large lahars can crush, abrade, bury, or carry away almost anything in their paths. Buildings and valuable lands may also be partially or completely buried. Even after years of eruption, some areas are still partially buried in lahar sand.

Rapid urbanization is one of the significant phenomena that make the unprecedented movements of people from rural to the burgeoning cities that resulted in dramatic growth of population, serious unemployment, pollution which generally strain environment and problem of solid waste generation (Malhotra, 1999). Urbanization in the Philippines is being equated to increased garbage and waste generation and pollution. Metro Manila, as of 1996, produced 6,379 tons per day garbage and waste. The major contributors of solid waste are the increasing number of spent rubber tires and the excessive lahar deposits that could be harmful to environment and the human health.

The consumption of tires for vehicle is increasing because of the rapid urbanization, and the large volume of lahar does not diminish. Thus, this will result in problems of space occupancy for landfills and proper disposal. In the Philippines, there are no


August 2021 | 128

exact data concerning the number of tires being dumped. In Metro Manila, according to the research conducted by the Metro Manila Urban Integration Study (MMUTIS), the registered motor vehicle is nearly 1 million. It has been estimated that there are more than 4 million of used/waste tires in stockpiles, landfills and backyards in our country today (Tujan, 2000).

The diminishing supplies and rising cost of natural resources used in road construction stimulated the investigation of the use of waste products such as rubber tire and lahar sand as partial substitute to fine aggregates. The consumption of vehicle tires is growing in demand because of the swift urbanization, and the lahar sand also increases due to the intense rainfall that may cause surface runoff producing lahar. Consequently, this results more industrial solid wastes. Environmental considerations on industrial solid waste and the diminishing landfill space are urgent concerns of the government and non-government organizations over the years. Some of the scrap tires are used as pots, chairs, and other decorative products, while the huge majority are landfilled, stockpiled, or discarded in non-environmental-friendly manners. Utilizing lahar sand is a great advantage to decrease the need for land fill spaces. Recycling waste products for construction is an effective strategy for waste management. Problems associated with efficient disposal of waste continue worldwide, and this is most critical in highly urbanized areas.

The study will focus on the utilization of lahar sand and rubber tire as partial replacement to fine aggregate of asphalt mix. It will also help to provide the construction industry alternative, cost-effective, and environment-friendly road construction materials. The study will help reduce the cost of asphalt pavement construction using crumb rubber tire (CRT) and lahar sand as an alternative substitute to fine aggregates.

2. MATERIALS AND METHODS

The research method applied in the study is the experimental method. Laboratory testing of materials for asphalt mix and testing of the properties of bituminous materials to determine the optimum design mix of crumb rubber tire and lahar sand as partial replacement to aggregate in asphalt mix production. The physical properties and mechanical properties of the mix design were compared to the ASTM standard and Marshall Design Criteria for Heavy Traffic.

The flow chart shows the procedure of activities to develop an asphalt pavement design mix using the crumb rubber tire and lahar sand as partial substitute for fine aggregate. The experimental design included the use of the following materials such as asphalt binder, Petron, Penetration Grade of 60/70, lahar sand, and crumb rubber tire. Natural sand was used as fine aggregate and hydrated lime as filler.

The asphalt mix developed in this study was the utilization of waste material (rubber) and a volcanic debris lahar sand as partial substitute to fine aggregate to lessen the cost of natural materials and the environmental impacts of the solid waste. This study will determine the physical and mechanical properties of the asphalt mix


August 2021 | 129

containing crumb rubber tire, asphalt binder (penetration grade 60/70), natural aggregate, and lahar sand.

This study will adapt an optimum asphalt content (OAC) of 5.07% and percentage of coarse and fine aggregates from a construction company. The DPWH Design Criteria (Marshall Mix Design) was followed to determine the optimum mix containing 5.07% of asphalt binder, lahar sand, and crumb rubber tire. A dense graded mix was prepared as asphalt mix surfacing where the particle size distribution differs mainly in terms of sizes. Figure 2 is the sample result of sieve analysis of the different materials used for the asphalt mix preparation.

According to Pagbilao (2002), continuously graded or dense graded mix consists of a blend of aggregates proportioned in such a way that it was compacted to give a dense interlocking structure of stones. The maximum aggregate size of 19.1 mm was used for the investigation. Table 4 is the DPWH Standard (Marshall Design Criteria) was used as a basis of compliance of the design mix being developed. The study considered the heavy traffic load (>1,000,000.00 equivalent axle load heavy vehicle) and criteria such flow, air voids, stability, voids in mineral aggregate, voids filled with asphalt.

The red line represents the ideal combination of different sizes of aggregate materials to be used for in the mix design. The black broken lines show the upper and lower limit which Grading D requirement of Department of Public Works and Highways (DPWH) Design Criteria. The different sizes of aggregates were used in order to improve properties of asphalt mix used for heavy traffic load.


August 2021 | 130

3. RESULTS AND DISCUSSIONS

The research method applied in the study is the experimental method. Laboratory testing of materials for asphalt mix and testing of the properties of bituminous materials to determine the optimum design mix of crumb rubber tire and lahar sand as partial replacement to aggregate in asphalt mix production. The physical properties and mechanical properties of the mix design were compared to the ASTM standard and Marshall Design Criteria for Heavy Traffic.

The Department of Public Works and Highways Design Criteria (Marshall Design) was adopted in order to arrive at the optimum mix using Lahar Sand and Crumb Rubber Tire as partial replacement for Fine Aggregates and the results are shown in Table 16. Marshall test method was used to evaluate the suitability of the asphalt design mix would satisfy the stability, flow, air voids, voids in mineral aggregates, and voids filled with asphalt limits.

The asphalt mixture properties with varying amounts of crumb rubber tire and Lahar Sand was evaluated to according to Marshall Design Criteria (DPWH Design Criteria). There are Fifteen (15) asphalt mix designs having an Asphalt Content based on the Controlled Mix. All laboratory tests were under the American Society for Testing and Materials and DPWH Design Standard for Marshall Criteria.

The amount of crumb rubber tire varies from 1%, 3% and 5% for each mix while the Lahar Sand varies from 10%, 20%, 30%, 40% and 50%. Each Mix Design has three (3) batches to have a reliable and discreet data and result. Out of 15 mixes (15), Mix Design 1-2 satisfied all the Marshall Design Criteria.

Table 2 shows the Mix Design 1-2 composed of asphalt design mix with 5.07% asphalt content, 1% crumb rubber tire, 20% Lahar Sand, 37% S1 and 48% coarse aggregate (crush gravel) which satisfied the DPWH Design Standard for Marshall Design Criteria of heavy traffic and the Design Criteria for Air Voids (VA), Voids in Mineral Aggregates (VMA), Flow Value and Voids Filled with Asphalt (VFA).

TABLE 2. TEST RESULTS OF MIX DESIGN 1-2

Mix Design 1-2 Final Remark PASSED

CRT 1% Lahar 20%

Stability (N) Flow (in) VA (%) VMA (%) VFA (%)

8857.33 10.43 4.59% 18.26% 74.83%

PASSED PASSED PASSED PASSED PASSED


August 2021 | 131

Graph 1. Summary of Marshall Stability Result

The graphed data obtained from the Marshall Stability Test shows the comparison among the mix design of all the specimen having a fixed amount of asphalt content and varying amounts of lahar sand and CRT. For the varying amounts of lahar sand ranging from ten to fifty percent with an interval of 10 and one percent CRT, all specimens passed the required for the Minimum DPWH Design Standard. For the mix design with three percent CRT and varying amounts of lahar sand, only specimen with fifty percent lahar sand passed the required for the Minimum DPWH Design Standard. As for the specimen with 5% CRT and varying percentage of lahar sand, no specimen passed the minimum requirement of DPWH.

Graph 2. Summary of Flow Values


August 2021 | 132

The graphed data of Flow Value in inches shows the comparison among the mix design of all the specimen having a fixed amount of asphalt content and varying amounts of lahar sand and CRT. For the varying amounts of lahar sand ranging from ten to fifty percent with an interval of 10 and one percent CRT, only specimen with 10% lahar sand exceeded the required maximum DPWH Design Standard while the rest passed. For the mix design with 3% CRT and varying amounts of lahar sand, only specimen with 30, 40, and 50 percent lahar sand passed the required for the Minimum and Maximum DPWH Design Standard while specimen with 10 and 20 percent lahar sand failed. As for the specimen with 5% CRT and varying percentage of lahar sand, all specimen exceeded the required maximum DPWH Design Standard, thus, failed.

Graph 3. Summary of Air Voids Result

The graphed data for the Air Voids (VA) result shows the comparison among the mix design of all the specimen having a fixed amount of asphalt content and varying amounts of lahar sand and CRT. For the varying amounts of lahar sand ranging from ten to fifty percent with an interval of 10 and one percent CRT, specimen with 30 and 40 percent lahar sand exceeded the required maximum DPWH Design Standard while the rest passed. For the mix design with 3% CRT and varying amounts of lahar sand, only specimen with 40 percent lahar sand passed the required for the Minimum and Maximum DPWH Design Standard while specimen with rest failed for exceeding the require maximum. As for the specimen with 5% CRT and varying percentage of lahar sand, all specimen failed in meeting the required for the DPWH Design Standard.


August 2021 | 133

Graph 4. Summary of Voids in Mineral Aggregates Result

The graphed data for the Voids in Mineral Aggregates (VMA) result shows the comparison among the mix design of all the specimen having a fixed amount of asphalt content and varying amounts of lahar sand and CRT. All specimen—with varying CRT percentage of 1, 3, and 5 and lahar sand with varying amount of lahar from 10 to 50 percent with interval of 10—passed the requirement of DPWH Design Standard.

Graph 5. Summary of Voids in Mineral Asphalt (VFA) Result

The graphed data for the Voids Filled with Asphalt (VFA) result shows the


August 2021 | 134

comparison among the mix design of all the specimen having a fixed amount of asphalt content and varying amounts of lahar sand and CRT. For the varying amounts of lahar sand ranging from ten to fifty percent with an interval of 10 and one percent CRT, specimen with 20, 30 and 50 percent lahar sand passed while the rest exceeded the required maximum DPWH Design Standard. For the mix design with 3% CRT and varying amounts of lahar sand, no specimen passed the required for the Minimum and Maximum DPWH Design Standard while specimen with rest failed for exceeding the require maximum. As for the specimen with 5% CRT and varying percentage of lahar sand, only specimen with 20% lahar sand passed the required for the minimum and maximum DPWH Design Standard.

The cost of materials for asphalt pavement is important in a large-scale production of asphalt mix. The cost analysis is very significant in determining the viability of the alternative materials used for the development of the asphalt mix.

Table 37 shows the cost of conventional asphalt mix of a 1000 meter length (1-km road) of asphalt pavement with 3 lanes with a 3.5 meter width and a 2” (0.050 m) thick asphalt mix. The composition of the conventional asphalt mix is: 42% of coarse aggregate (1/2”, ¾” and 3/8”), 57% of fine aggregate, 1% of mineral filler, and 5.07% of asphalt binder (Penetration Grade 60/70).

Table 38 shows the cost of materials of the asphalt mix that contains lahar sand and crumb rubber tire. Crumb rubber tire is obtained for free with a very minimal hauling cost.

Tables 37 and 38 show the cost of materials of the two different asphalt mix compositions. The asphalt mix that contains 1% of crumb rubber tire and 20% of lahar sand is cheaper by 8.55% (P37, 568.00 per kilometer) than the conventional asphalt that contains 23% of fine aggregates. A total of P37, 568.00 per kilometer is the savings in the construction of materials if the asphalt mix with lahar sand and crumb rubber tire will be utilized in the asphalt production of road pavement construction.

Table 37. Cost of Control Mix Design

Materials Percentage

Composition Cost per Unit

Volume

(cu. m) Cost of Materials

Coarse

Aggregates 42% 650

per cu.

M 224.028 Php 145,618.20

Fine

Aggregates 57% 700

per cu.

M 304.038 Php 212,826.60

Filler 1% 25 per kg 5.334 Php 32,484.06

Asphalt 5.07% 1800 per cu.

M 27.04338 Php 48,678.08

Total Cost Php 439,606.94


August 2021 | 135

4. FINDINGS AND CONCLUSIONS

Based on the physical property test done on the materials, it can be said that the lahar sand and crumb rubber tire were utilized as a partial substitute to fine aggregate and were proportioned using the grading limits of DPWH – Grading D. From the findings of the physical property tests, it can be concluded that the utilization of lahar sand and crumb rubber tire was characterized as fine aggregate.

The stability drops when the amount of CRT increases and an increase of stability when the amount of lahar sand increases. The increasing amount of CRT decreases the stability while the increasing the amount of lahar sand increases the stability.

The stability drops when the amount of CRT increases and an increase of stability when the amount of lahar sand increases. The increasing amount of CRT decreases the stability while the increasing the amount of lahar sand increases the stability.

Mix Design 1-2 (20% of lahar sand, 1% of CRT, 37% of natural fine sand, 42% of coarse aggregate, and 5.07% of asphalt binder) satisfied all the Marshall Design Criteria of DPWH Design Standard for heavy traffic loading.The design mix with the fixed optimum asphalt content (OAC) of 5.07%, 20% of lahar sand, 1% of CRT, 37% of natural fine sand, and 42% of coarse aggregate satisfied all the Marshall design criteria.

5. RECOMMENDATIONS

Mix design 1-2, containing 20% of lahar sand and 1% of CRT, has lower materials cost than the conventional asphalt mix. The mix design having 20% of lahar sand, 1% of CRT, 37% of natural fine sand, 42% of coarse aggregate, and 5.07% asphalt binder (Pengrade60/70) is recommended for asphalt pavement construction. It is suggested that further studies with full replacement of fine aggregate by CRT and lahar sand be undertaken. The mix design having 20% of lahar sand, 1% of CRT, 37% of natural fine sand, 42% of coarse aggregate, and 5.07% asphalt binder (Pengrade60/70) is suggested to undergo more tests like wet and dry compressive

Table 38. Cost of Mix Design 1-2

Materials Percentage Composition

Cost per Unit Volume

(cu. m) Cost of Materials

Coarse

Aggregates 42 650 per cu. M 224.028 Php 145,618.20

Fine

Aggregates 37 700 per cu. M 197.358 Php 138,150.60

CRT 1 free* 5.334 Php 250.00

Lahar 20 650 per cu. M 106.68 Php 69,342.00

Asphalt 5.07 1800 per cu. M 27.0433

8 Php 48,678.08

* Crumb Rubber Tire = Cost of Hauling: P250/truck load (20 sacks)

Total Cost

Php 402,038.88


August 2021 | 136

strength, IRS, dynamic stability, and a field exposure. It is suggested that further studies be made for asphalt mix formulation using the wet process approach with certain amount of lahar sand. Other researches are recommended to also consider different formulation; larger percentage of coarse aggregates and larger percentage of asphalt binder (Penetration grade 60/70).

REFERENCES

[1] Petron Corporation, Asphalts, Petron Brochure in Asphalt. Petron Corporation, Makati Ave. Metro Manila, Philippines, 2000 [2] Brien, D. Asphalt Mix Design-Developments in Highway Pavement Engineering, London: Applied Science Publishers, 1978. [3] Department of Energy. Philippine Energy Plan 1999-2008, Fort Bonifacio, Metro Manila, 2000. [4] BusinessDictionary. (2016). BusinessDictionary. Retrieved from Usability: http://www.businessdictionary.com/definition/usability.html [5] Department of Public Works and Highways. Standard Specifications for Public Works and Highways, Volume II, Manila, Philippines, 1995. [6] Dickey, John W., Miller Leon H. Road Project Appraisal for Developing Countries”, John Wiley & Sons, London, UK, 1984. [7] Hossain, Mustaque, Sadeq, Mustafa, Funk, Louis P., Maag, Rodney. A Study of Tire Chips as Road Construction Material, Department of Civil Engineering, Kansas State University, Manhattan, Kansas 66506, 1996. [8] Dasig Jr., D. (2014, August). International Journal of Business Information Systems Strategies (IJBISS) . Retrieved from A study on the sectors of economy serviced by pre-industry system developers among companies in Metro Manila: A tool for Business Reengineering: https://arxiv.org/ftp/arxiv/papers/1409/1409.7277.pdf [9] Kandhal, Prithvi S. Waste Materials in Hot Mix Asphalt-An Overview. National Center for Asphalt Technology, NCAT Report No. 92, 1992. [10] Lavansiri, D. Pavement Design and Construction, Chulalongkorn University, Thailand, 1992. [11] Mc Millan, C., Kwan, A., Donovan, H., Enslen, P., Horton, B. Current Asphalt Rubber Developments in Alberta”, Alberta, Pelham Road Project Report, USA, 2000. [12] Pagbilao, Dominador, S. Training Manual in Asphalt Mix Design, Integrated Research and Training Center-Technological University of the Philippines. Manila, 1997. [13] Schnormeier, Russell. Recycling Tires into Pavement, Resource Recycling, Asphalt Rubber Producers Group, Phoenix, Arizona, 1988. [14] Way, George B. Pavement Design-Where the Rubber meets the Rubber. Arizona Department of Transportation, Arizona, USA, 1999. [15] Scrap Tire Management Council. Scrap Tire Use/Disposal Study 199 Update. Washington, DC, 1995. [16] Thagesen, Bent. Highway & Traffic Engineering in Developing Countries. London, 1995.


August 2021 | 137

[17] Transport Research Laboratory (TRL). A Guide to the Pavement Evaluation and Maintenance of Bitumen-Surfaced Roads in Tropical and Sub-tropical Countries. Overseas Road Note 18, Department for International Development, Overseas Centre, Transport Research Laboratory, Crowthorne, Berkshire, United Kingdom, 1999. [18] Tujan, A. The State of the Philippine Environment. Ibon Foundation, Inc. Manila, Philippines, 2000. [19] Utah Department of Transportation. Rubberized Asphalt. Technical Bulletin MT-03.06 page 2, Utah, USA, 2003. [20] Balige, Marcela. “Crumb Rubber Bituminous Mixes from Waste Tires in Argentina.” Asphalt Magazine, Brasilia, Brazil, 2004. [21] Chamberlin, B. and Gupta, P. “Use of Scrap Automotive Tire Rubber in Highway Construction.” Special Report 85, Engineering Research and Development Bureau, New York State DOT, Albany, New York, 1986. [22] Edwards, A., Kirk S., Sese, J. “Making Good Use of Volcanic Ash in the Philippines”, pages 1-4 [23] Eldin, Niel N. “Road Construction: Materials and Methods.” Journal in Environmental Engineering, Vol. 128, Issue 5, USA, 2002. [24] Faustino, R., Ford, W., O’Connnell, M., Valencia N. “Making Effective Use of Volcanic AshmIn Road-Building in the Philippines”, Proceedings of the Eastern Asia Society For Transportation Studies. Vol. 5, page 868 – 876, 2005 [25] Ghaly, A. “Properties of Asphalt Rubberized with Waste Tires Crumb”, Journal of Solid Waste Technology and Management. Vol. 26, No.1, 1999. [26] Heitzman, M. “An Overview of Design and Construction of Asphalt Paving Materials with Crumb Rubber Additives”, Paper presented at the 71st, Annual Meeting of Transportation Research Board, Washington, DC, 1992. [27] Hossain, M., Sadeq, M., Funk, L., and Maag, R. “A Study of Chunk Rubber from Recycled Tires as a Road Construction Material.” Proceedings of the 10th Annual Conference on hazardous Waste Research, Kansas State University, Kansas City, USA, 2000. [28] Jorillo, P., Pulmano, V., Gallardo, R. “Potentials of Waste and Recycled Materials in Construction Projects.” DPWH Technical Journal, Quezon City, Philippines, 2000. [29] Maunsell, Special Provisions-Dense Graded Asphalt Pavement, Manila North Tollways Project, Manila, Philippines, 2000. [30] Naik, Tarun R., Singh, S S. “Utilization of Discarded Tires as Construction Materials for Transportation Facilities.” Center for By-Products Utilization, Report No. CBU, Department of Civil Engineering, University of Wisconsin-Milwaukee. USA, 1991. [31] Pagbilao, D., Aala, M., Agbuya, J., Labarda, A., Pagilagan, R. “Properties of Crumb Rubber Modified Asphalt & Asphalt Mixture.” Proceeding of the 5th International Conference of Civil Engineering, Manila, Technological University of the Philippines-Integrated Research and Training Center, Nihon University. Manila, 2002. [32] Pennsylvania Asphalt Pavement Association, (2003), Hot Mix Asphalt Design Guide. Retrieved: August 2017.http://www.pahotmix.org/pdf/Design_Guide.pdf


August 2021 | 138

[33] Scrap Tire Management Council, Asphalt Material Description of Scrap Tires, Page 1-2, Retrieved August 2017, http://www.tfhrc.gov/hnr20/recycle/waste/st2.htm. [34] Crumb Rubber Tire, https://www.freedoniagroup.com/industry-study/world-rubber-tire-2282.htm?, Retrieved August 2017 [35] Crumb Rubber Tire, https://www.freedoniagroup.com/industry-study/world-rubber-3381.htm Retrieved August 2017 [36] Crumb Rubber Tire, http://www.topgear.com.ph/news/industry-news/michelin-tires-not-bananas-campaign-a1503-20170128, Retrieved August 2017 [37] Lahar Sand, https://pubs.usgs.gov/pinatubo/janda/,Retrieved August 2017 [38] Export of Lahar Sand, http://www.philstar.com/news-feature/737700/zambales-export-lahar-sand, Retrieved August 2017 [39] Article - Lahar Sand, https://volcanoes.usgs.gov/vhp/lahars.html, Retrieved August 2017

Documents

ANALYSIS OF MECHANICAL PROPERTIES OF ASPHALT MIX …