Use of Glass Fibers in Thin Lift Stone Mastic Asphalt (SMA) Production for Low Volume Roads

Superpave and Marshall mix designs using local aggregates were done to study the suitability of the Superpave mix design as compared with the Marshall mix design for low-volume roads, especially shoulders. The project site was Kansas Route 177 in northeast Kansas. Three locally available aggregates, crushed limestone and coarse and fine river sands, were used in this study. Five blends with varying proportions of coarse and fine river sands were selected. Mix samples were compacted in the Superpave gyratory compactor with the applicable number of gyrations and were compacted with the Marshall hammer by using 50 blows per face. Bulk densities of the compacted samples and maximum specific gravities of loose samples also were measured for each blend. The results show that the Superpave mix design for low-volume roads and shoulders results in lower estimated asphalt content than does the Marshall method. The required asphalt content increases as the proportion of coarse river sand increases in the mix. Superpave requirements for the voids filled with asphalt (VFA) for low-volume traffic, that is, less than 0.3 million equivalent single-axle loads, appeared to be too high. High asphalt film thicknesses were computed for the mixtures that did not meet the Superpave VFA requirements. Lowering the design number of gyrations (Ndes) for compaction of samples would result in increased asphalt requirement for the Superpave mixture with a given gradation.

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Otta Seals and Gravseals as Low-Cost Surfacing Alternatives for Low-Volume Roads: Experiences in South Africa

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1819b-43 ◽

2003 ◽

Vol 1819 (1) ◽

pp. 338-342 ◽

Cited By ~ 2

Author(s):

Simon Oloo ◽

Rob Lindsay ◽

Sam Mothilal

Keyword(s):

South Africa ◽

Low Cost ◽

Cost Savings ◽

Cost Effective ◽

Field Trials ◽

Low Volume Roads ◽

Kwazulu Natal ◽

Traffic Volumes ◽

Low Volume ◽

To Come

The geology of the northeastern part of the province of KwaZulu–Natal, South Africa, is predominantly alluvial with vast deposits of sands. Suitable gravel sources are hard to come by, which results in high graveling and regraveling costs brought about by long haul distances and accelerated gravel loss. Most gravel roads carry fewer than 500 vehicles per day of which less than 10% are heavy vehicles. The high cost of regraveling has led to consideration of upgrading such roads to surfaced standard, even though traffic volumes do not justify upgrading. Traditional chip seals are expensive and cannot be economically justified on roads that carry fewer than 500 vehicles per day. The KwaZulu–Natal Department of Transport is actively involved in efforts to identify cost-effective alternative surfacing products for low-volume roads. Field trials were conducted with Otta seals and Gravseals, which have been used successfully in other countries, as low-cost surfacing products for low-volume roads. The Otta seal is formed by placing graded aggregates on a relatively thick film of soft binder that, because of traffic and rolling, works its way through the aggregates. Gravseal consists of a special semipriming rubberized binder that is covered by a graded aggregate. Both Otta seals and Gravseals provide relatively flexible bituminous surfaces suitable for low-volume roads. Cost savings are derived mainly from the broad aggregate specifications, which allow for the use of marginal materials.

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Performance Characterization of Stone Mastic Asphalt using Steel Fiber

Journal of Advanced Industrial Technology and Application ◽

10.30880/jaita.2021.02.02.003 ◽

2021 ◽

Vol 02 (02) ◽

Author(s):

Ekarizan Shaffie ◽

◽

H.A. Rashid ◽

Fiona Shiong ◽

Ahmad Kamil Arshad ◽

...

Keyword(s):

Steel Fiber ◽

Mechanical Performance ◽

Permanent Deformation ◽

Asphalt Mixture ◽

Moisture Susceptibility ◽

Mastic Asphalt ◽

Bitumen Content ◽

Stone Mastic Asphalt ◽

The Stability ◽

Marshall Stability

Stone Mastic Asphalt (SMA) is a gap-graded hot mixture designed to provide higher resistance towards permanent deformation and rutting potential by 30% to 40% more than dense-graded asphalt, due to its stable aggregate skeleton structure. However, compared to other types of hot mix asphalt, SMA unfortunately has some shortcomings in term of its susceptibility towards moisture-induced damage due to its structure and excessive bitumen content in the composition. This research aims to assess the performance of a SMA mixture with steel fiber by enhancing overall stability, abrasion resistance, and, most importantly, moisture susceptibility. This study involved the incorporation of various steel fiber proportions of 0%, 0.3%, 0.5% and 0.7% by the total weight of mixture. The steel fiber modified SMA was made up of 6.0% PEN 60/70 bitumen content. The performance of SMA were evaluated through Marshall stability and flow test, Cantabro loss test and indirect tensile strength test. The results obtained from the testing showed that the incorporation of steel fiber is significantly effective to enhance the resistance towards moisture damage, while increasing the stability and reducing the abrasion loss of SMA mixture, compared to conventional mixture. Overall, it can be concluded that the addition of steel fiber in asphalt mixture specifically SMA, has improved the mechanical performance in the application of asphalt pavement with the optimum steel fiber proportion of 0.3% by the weight of mixture. The developed models between the independent variables and responses demonstrated high levels of correlation. The study found that Response Surface Methodology (RSM) is an effective statistical method for providing an appropriate empirical model for relating parameters and predicting the optimum performance of an asphaltic mixture to reduce flexible pavement failure.

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Laboratory investigation of the effect of nano Caco3 on rutting and fatigue of stone mastic asphalt mixtures

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.126127 ◽

2022 ◽

Vol 317 ◽

pp. 126127

Author(s):

Amir Mohammad Yarahmadi ◽

Gholamali Shafabakhsh ◽

Adel Asakereh

Keyword(s):

Laboratory Investigation ◽

Asphalt Mixtures ◽

Mastic Asphalt ◽

Stone Mastic Asphalt

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