Inā ua hele ʻoe i kekahi hōʻikeʻike kālepa i kēia mau lā aku nei—ʻo bauma, CONEXPO, a i ʻole ke Ao o ka Asphalt—ua lohe paha ʻoe i nā mea hana e hoʻolei ana i ka huaʻōlelo " rap recycling hot asphalt mixing plant solutions " me he mea lā ʻo ia ka berena ʻokiʻoki aʻe. A ʻoiaʻiʻo? He ʻoiaʻiʻo ka hype. Ma ka hānai ʻana i nā ʻāpana wili o ka pavement kahiko i loko o kahi pahu wela loa, ke hōʻemi nei nā mea hana i nā bila maka a hiki i ka 35%. Akā eia ka mea kīkēkē: ʻaʻole mākaukau nā mea kanu āpau e moni i ka 40% RAP me ka ʻole o ka hoʻololi ʻana i kāna hui i loko o kahi ʻōpala crispy. No laila, pehea ʻoe e loaʻa ai ke kālā ma luna o nā mālama kālā me ka nānā ʻole i kāu tank metrics maikaʻi? E ʻeli kākou.
ʻAʻole wale ka Reclaimed Asphalt Pavement (RAP) he "pōhaku ʻeleʻele." Loaʻa iā ia ka bitumen kahiko, ka mea hoʻopihapiha mineral maikaʻi, a me nā aggregates angular. Ke hoʻokomo ʻoe i kēia mea i loko o kahi pahu maʻamau 160 °C, paʻakikī ka mea hoʻopaʻa kahiko, e alakaʻi ana i ka nahā mua. Hoʻoponopono nā hoʻonā hana hui ʻala wela hou i kēia ma:
ʻO ka laina lalo: ʻaʻole ʻoe e hana hou wale nei; ke hana hou nei ʻoe i ka rheology o ka mea hoʻopaʻa i hana ai ka hui e like me ka puʻupaʻa, a ʻoi aku paha.
Ua noho aliʻi nā pahu counter-flow i ka mākeke no nā makahiki he ʻumi, akā ʻo ka hoʻololi ʻana i kahi hoʻolālā parallel-flow e ʻae i kahi kiko hoʻolauna RAP kiʻekiʻe aʻe—a hiki i ka 50%—me ka ʻole o ka hōʻike ʻana i ka mea i nā kahawai kinoea wela. ʻO ka hopena? ʻO ka emi ʻana o ka oxidation, ka haʻahaʻa o ka carbonyl index, a me kahi pae penetration post-blend palupalu.
He mea nui ka pololei. ʻO ka hewa ±1% ma kahi hale hana 200-tona-i kēlā me kēia lā ua like ia me 2 tona o ka mea hoʻopaʻa i hoʻonele ʻia i kēlā me kēia pule. ʻO nā kāʻei kaupaona hou me nā VFD e hōʻea i ka ±0.2% tolerance, no laila e noho mau ana kāu hui i loko o nā spec a hauʻoli nā mea nānā o ke keʻena.
Hoʻopulu nā kāʻei kahiko i ka mahana o 140 °C. ʻAkaʻaka nā mana i hoʻoikaika ʻia e Kevlar i ka mahana o 180 °C, e mau ana no 30% ka lōʻihi a e hōʻemi ana i ka manawa hana ʻole i hoʻolālā ʻia. ʻAe, ʻoi aku ke kumukūʻai o 20% ma mua, akā e mālama ʻoe i ʻekolu mau hoʻololi kāʻei i loko o ʻelima mau makahiki.
I ka makahiki 2022, ua hoʻoponopono hou ʻo Austin Paving i kāna pahu o ka wā 1970 me kahi pūʻolo hoʻonā hui ʻana o ka asphalt wela rap : kahi mea hānai RAP 50-tona, kahi mea hoʻomehana ʻaila wela 12 MBtu/hr, a me nā skid rejuvenator. Ma luna o 12 mahina:
Uku? He ʻumikumamāhiku mahina, me ka loaʻa kālā i nalowale mai ʻelua pule ua. ʻAʻole maikaʻi ʻole no kahi mea kanu i "hiki ʻole ke lawelawe i ka RAP kiʻekiʻe" i ka makahiki 2019.
Ua hōʻike ʻia ka noiʻi a NCAT i ka makahiki 2021 he 40% RAP mix me 0.4% rejuvenator e lanakila ana ma luna o ka puʻupaʻa ma ka luhi beam ma 200 micro-strain. ʻO ke akamai ke koho ʻana i ka rejuvenator kūpono: ʻaila ʻala no nā mahana haʻahaʻa, maltene-based no nā mahana kiʻekiʻe.
Me ka hoʻomehana mua ʻana o ka RAP haʻahaʻa haʻahaʻa, hāʻule maoli nā VOC i ka 15% i hoʻohālikelike ʻia me nā hui puʻupaʻa pololei, no ka mea ke pani nei ʻoe i kahi ʻāpana o ka mea hoʻopaʻa puʻupaʻa—nona ka mea hana ke kumu hoʻokuʻu maoli.
Hoʻomaka nā hana hou ma $350k, ʻaʻole ka hōʻailona $3 miliona o kahi ʻāpana greenfield. Hāʻawi ka hapa nui o nā DOT mokuʻāina i ka ʻae ʻia o ka hui ʻana inā ʻoe e hala i nā hoʻokolohua like puʻupaʻa, no laila hiki iā ʻoe ke mālama i kāu mau silos a me nā ukana kalaka.
Ma mua o kou kau inoa ʻana i kēlā PO, e holo i kēia papa inoa ʻōlelo lapuwale:
ʻĀ, eia kekahi ʻōlelo aʻoaʻo hoʻopunipuni: e kūkākūkā i kahi "paukū hana" e hoʻopaʻa ana i ka uku hope loa i ka hoʻokō ʻana i kāu helu RAP i manaʻo ʻia no 30 mau lā i ka lālani. E hilinaʻi mai iaʻu, e hoʻomau ia i nā ʻenehana lawelawe o ka OEM ma kahi a hiki i ka wā e ʻōmaʻomaʻo ai nā helu.
No laila ua holo ʻoe i kahi pailota 200-tona a ʻike maikaʻi kou mau ʻiʻo. I kēia manawa he aha? E hoʻonui i ka 10% i kēlā me kēia ʻelua pule. No ke aha ka wikiwiki o ka nahe? Makemake ʻoe i kāu poʻe hana kahua e ʻike i ka rutting mua ma mua o ka lilo ʻana i mea poʻo poʻo palapala hōʻoia. Eia kekahi, e hoʻoponopono i kāu polokalamu QC e hōʻailona i kekahi hāʻule ʻana o ka ʻike asphalt maikaʻi ma lalo o 5.2%. He ʻeha ia i ka wā mua, akā i ka manawa e aʻo ai ka algorithm i kāu loli RAP, hāʻule nā makaʻala i kokoke i ka zero. I kēlā manawa, hiki iā ʻoe ke haʻaheo e pili ana i ka " rap recycling hot asphalt mixing plant solutions " ma kāu blog hui me ka ʻole o ke kau ʻana i kou mau manamana lima ma hope o kou kua.
Ke hoʻāʻo nei nā ʻoihana hoʻomaka i nā kāmela ʻike AI e heluhelu ana i ka gradation RAP i ka manawa maoli, e hoʻoponopono ana i ka lele ʻana o ka mea puhi ma ka lele. I kēia manawa, ke kālepa ʻia nei nā hōʻaiʻē kalapona ETS o ʻEulopa ma €90/ton CO₂—e hoʻololi ana i kēlā me kēia piʻi ʻana o 10% RAP i kahi uku $0.85/ton. Inā hoʻokō nā mea hana kānāwai ma ka mokuʻāina i nā tariff like, hiki ke pālua ka tailwind waiwai no nā hui RAP kiʻekiʻe i ka pō. ʻO ka hopena: ʻo nā mea kanu e hoʻopukapuka kālā i kēia lā e paʻi i nā margins i ka lā ʻapōpō ke hoʻomaka nā mea kikoʻī e noi no nā EPD (Environmental Product Declarations) ma kēlā me kēia pepa noi.
Mākaukau e ʻomi i kēlā me kēia keneta mai kāu tona aʻe ʻoiai ke kāhea nei ka hoʻokūkū e pili ana i ka "nui loa o ka RAP"? E hoʻonui i nā hopena mea kanu hoʻohuihui asphalt wela i hōʻoia ʻia a nānā i kāu mau waiwai - a me kāu helu hoʻomau - e piʻi aʻe.