Asfalt campuran suam (WMA) merupakan satu teknologi lestari yang dibangunkan untuk mengurangkan suhu pencampuran dan pemadatan, tetapi boleh dihasilkan dengan menggunakan loji asphalt dan mesin penurap lazim. Dari segi aspek alam sekitar dan kelestarian, WMA dapat mengurangkan pelepasan gas rumah hijau secara berkesan. Oleh sebab suhu penghasilan yang lebih rendah, WMA lebih mudah terdedah kepada kerosakan lembapan kerana pengeringan agregat yang tidak lengkap menyebabkan lembapan terperangkap. Lebihan lembapan ke dalam turapan asfalt akan merosotkan kualiti turapan dan membawa kesan buruk ke atas bahan turapan asfalt. Bahan pemadatan suam dari India dinamakan Zycotherm ditambah dalam penghasilan WMA dan keberkesanannya sebagai ejen anti-pelucutan telah diselidiki. Untuk mensimulasikan keadaan sebenar di tapak, campuran asfalt telah didedahkan kepada penuaan jangka panjang dan kerosakan kelembapan secara serentak. Prestasi WMA dan asfalt campuran panas (HMA) dinilai dari segi kepadatan, kebolehkerjaan, kekuatan tegangan dan ricih. WMA didapati lebih mudah dipadatkan dan diterapkan berbanding dengan HMA. WMA juga dibuktikan mempunyai rintangan kelembapan yang lebih baik selepas didedahkan kepada pelaziman kelembapan. Penggunaan agregat berkubik dalam campuran asfalt menunjukkan prestasi yang lebih baik dari segi tegangan dan ricih. Pembentukan agregat patah berpunca daripada bentuk agregat dan bukannya orientasi agregat. Hal ini disebabkan kebanyakan agregat yang patah adalah agregat biasa yang memanjang dan bersepih. Agregat jenis ini mudah pecah di sepanjang satah lemah. Analisis terhadap penggredan agregat selepas pemadatan dan ujian prestasi membuktikan agregat berkubik terdegradasi kurang daripada agregat biasa.
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Warm mix asphalt (WMA) is a sustainable technology developed to lower the mixing and compaction temperatures but can be prepared using conventional asphalt plant and paving machineries. In terms of environmental and sustainability aspects, WMA can effectively reduce greenhouse gas emissions. Due to its lower production temperature, WMA is more prone to moisture damage due to incomplete drying of aggregate thus results in trapped moisture. Excessive intrusion of moisture into the asphalt pavement would deteriorate the pavement quality and have adverse impact on asphalt pavement. A warm compaction additive from India named Zycotherm was added to produce WMA and its effectiveness as an anti-stripping agent was investigated. To simulate the actual condition on site, the asphalt mixtures were subjected to simultaneously long term aging and moisture damage. The performance of WMA and HMA were evaluated in terms of compactability, workability, tensile and shear strengths. From the investigation, WMA can be more easily compacted and more workable compared to HMA. WMA exhibited better moisture resistance after subjected to moisture conditioning. The utilization of cubical aggregates in asphalt mixture showed better performance in terms of tensile and shear stresses. From image analysis, WMA incorporating cubical aggregates demonstrated lower percentage adhesive failure which proved the effectiveness of Zycotherm. The formation of fractured aggregates was primarily due to the aggregate shape instead of aggregate orientation. This is because most of the broken aggregates were elongated or flaky normal aggregates that breaks easily along their weak plane when subjected to applied loads. Analysis on the aggregate gradation after compaction and performance tests proved that cubical aggregates degraded less than normal aggregates.
Evaluation of the combined effects of long term aging and moisture damage on asphalt mixture incorporating cubical aggregates and zycotherm / Tan Shin Ru