{"id":712,"date":"2026-05-27T07:46:02","date_gmt":"2026-05-27T07:46:02","guid":{"rendered":"https:\/\/rock-crusher-tractor.com\/?p=712"},"modified":"2026-05-27T07:46:02","modified_gmt":"2026-05-27T07:46:02","slug":"thor-st-soil-stabilizer-korean-rural-road-fdr-guide","status":"publish","type":"post","link":"https:\/\/rock-crusher-tractor.com\/ko\/thor-st-soil-stabilizer-korean-rural-road-fdr-guide\/","title":{"rendered":"THOR ST \ud1a0\uc591 \uc548\uc815\uc81c \u2014 \ud55c\uad6d \ub18d\ucd0c \ub3c4\ub85c FDR \ubc0f \ub178\ubc18 \uc900\ube44 \uc644\ubcbd \uac00\uc774\ub4dc"},"content":{"rendered":"
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THOR ST Soil Stabilizer \u2014 Complete Operation Guide for Korean Rural Road FDR and Subgrade Preparation<\/h1>\n

The THOR ST mills the existing failed road base to 200mm depth, mixes in stabilising binder from the DCW 2.2, and produces a homogeneous stabilised layer in a single machine pass. This is FDR \u2014 Full-Depth Reclamation \u2014 and it is the alternative to demolishing and rebuilding the Korean rural road.<\/p>\n

THOR ST Road Stabilization Enquiry<\/a><\/p>\n<\/div>\n<\/div>\n

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Korean rural roads \u2014 agricultural access roads, highland farm tracks, and the 4-metre-wide agricultural roads connecting farming communities \u2014 deteriorate through a predictable failure mechanism: surface load over weak or saturated base material produces rutting, base pumping, and eventually complete pavement collapse. The conventional rehabilitation response is excavation and replacement \u2014 expensive, disruptive, and requiring material import. Full-Depth Reclamation (FDR) with the THOR ST soil stabilizer is the alternative: the existing failed base material is milled to full treatment depth, blended with a structural binder, and recompacted as a homogeneous stabilised layer, eliminating both the excavation cost and the imported aggregate requirement.<\/p>\n

This guide covers the THOR ST machine specification, the FDR operation sequence, binder selection for Korean road conditions, depth settings for different base failure scenarios, and how the THOR ST differs from both the agricultural THOR 2.4 \uc11d\uc7ac \ubd84\uc1c4\uae30<\/a>\u00a0and conventional road base replacement methods.<\/p>\n

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THOR ST Confirmed Specifications \u2014 From the Official Watanabe Brochure<\/h2>\n

\"THOR<\/p>\n

\ubaa8\ub4e0 \uc0ac\uc591\uc740 \uc640\ud0c0\ub098\ubca0 \uacf5\uc2dd \uc81c\ud488 \ube0c\ub85c\uc154\uc5d0 \ub098\uc640 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n

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250 CV<\/span><\/div>\n
CVT \uc758\ubb34\uc801<\/div>\n<\/div>\n
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92<\/div>\n
Kennametal RK4 bits<\/div>\n<\/div>\n
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0\u2013200 mm<\/span><\/div>\n
Milling depth range<\/div>\n<\/div>\n
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5,300 \ud0ac\ub85c\uadf8\ub7a8<\/span><\/div>\n
\uae30\uacc4 \uc911\ub7c9<\/div>\n<\/div>\n
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0.5\u20131.5 km\/h<\/span><\/div>\n
\uc791\uc5c5 \uc18d\ub3c4<\/div>\n<\/div>\n
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1000 RPM<\/span><\/div>\n
PTO \uc18d\ub3c4<\/div>\n<\/div>\n<\/div>\n
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Transport dimensions (from official brochure):<\/p>\n

Length: 2,960 mm \u2014 Width: 2,745 mm \u2014 Height: 2,615 mm. These transport dimensions are critical for Korean road access planning \u2014 the THOR ST at 2,745 mm transport width requires road clearance confirmation before mobilising to narrow Korean rural road sections.<\/p>\n<\/div>\n

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How the THOR ST Differs from the Agricultural THOR 2.4 \u2014 A Fundamental Distinction<\/h2>\n

The THOR ST and the THOR 2.4 share the Watanabe name and a rotor-based working mechanism, but they are fundamentally different machines designed for fundamentally different applications. Conflating them \u2014 or attempting to substitute one for the other \u2014 produces either poor results or machine damage:<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n
Feature<\/th>\nTHOR ST (Soil Stabilizer)<\/th>\nTHOR 2.4 (Stone Crusher)<\/th>\n<\/tr>\n<\/thead>\n
Primary function<\/td>\nMill road base to 200mm, mix with binder to produce stabilised layer<\/td>\nFragment embedded stones to below 5 cm in agricultural fields<\/td>\n<\/tr>\n
Cutting tool<\/td>\n92 Kennametal RK4 tungsten carbide bits (road milling grade, high impact)<\/td>\n90 + 6 tungsten carbide teeth (agricultural grade)<\/td>\n<\/tr>\n
Cutting action<\/td>\nDowncut milling \u2014 bits rotate downward into pavement material, producing uniform fine particles for binder mixing<\/td>\nImpact fracture \u2014 teeth hit stones at high velocity to fracture them<\/td>\n<\/tr>\n
\uc791\uc5c5 \uc18d\ub3c4<\/td>\n0.5\u20131.5 km\/h \u2014 slow, precise depth control<\/td>\n1.0\u20133.0 km\/h \u2014 faster, coverage-focused<\/td>\n<\/tr>\n
Power requirement<\/td>\n250 CV, CVT mandatory (sustained high torque at low speed)<\/td>\n180 HP minimum, standard gearbox<\/td>\n<\/tr>\n
Output material<\/td>\nFine mixed layer (existing base + binder) ready for compaction \u2014 stays in place<\/td>\nCrushed stone fragments \u2014 requires CT-2100 collection and removal<\/td>\n<\/tr>\n
Use on agricultural fields?<\/td>\nNo \u2014 road milling\/stabilisation only. Agricultural field use wastes the machine’s capability and produces the wrong output for seedbed preparation.<\/td>\nYes \u2014 primary agricultural application<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

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The FDR Process \u2014 How THOR ST + DCW 2.2 Rebuild a Failed Korean Road Base<\/h2>\n

\"Korean<\/p>\n

Full-Depth Reclamation with the THOR ST is a multi-machine, sequential process. Each step must be completed correctly before the next begins \u2014 incorrect sequencing produces a stabilised layer with non-uniform binder distribution, reducing the structural improvement from what the FDR investment should deliver:<\/p>\n

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Step 1: Base Assessment<\/div>\n

Before any machine is deployed: core samples confirm treatment depth requirement (typically 150\u2013200 mm for agricultural road rehabilitation), existing base material classification (granular, stabilised, or full pavement), moisture content at treatment depth, and binder type selection. Assessment determines whether 150 mm or 200 mm depth setting is appropriate for the specific failure pattern on this road section.<\/p>\n<\/div>\n

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Step 2: DCW 2.2 Binder Application<\/div>\n

\uadf8\ub9cc\ud07c DCW 2.2 \ubc14\uc778\ub354 \uc2a4\ud504\ub808\ub354<\/a> applies dry granular binder (cement, quicklime, or fly ash blend) to the road surface ahead of the THOR ST pass. Application rate (Kg\/m\u00b2) is set through the electronic cab control system based on the binder design mix for the specific base material and target bearing capacity. The 2,140 mm working width covers the full carriageway in one pass on standard Korean agricultural roads (3.0\u20134.0 m wide).<\/p>\n<\/div>\n

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Step 3: THOR ST Milling and Mixing<\/div>\n

THOR ST follows the DCW 2.2 binder application pass immediately (within 30\u201360 minutes to prevent binder hydration before mixing). The THOR ST’s 92 Kennametal RK4 bits mill the existing base material to the specified depth (0\u2013200 mm, set hydraulically from the cab). The milling action simultaneously breaks up the existing pavement material and mixes it with the surface-applied binder. Forward speed: 0.5\u20131.0 km\/h. The CVT tractor automatically adjusts ratio to maintain constant rotor speed under variable load resistance across different base material hardness zones.<\/p>\n<\/div>\n

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Step 4: Grading and Profiling<\/div>\n

Immediately after the THOR ST pass, a motor grader or tractor blade grades the mixed stabilised material to the design road profile \u2014 restoring crown (cross-fall), correcting the longitudinal gradient, and removing surplus material from the edge zones. This step must be completed before initial setting begins \u2014 typically within 1\u20132 hours of THOR ST mixing for cement binder, longer for lime binder.<\/p>\n<\/div>\n

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Step 5: Compaction and Curing<\/div>\n

Vibrating roller compaction immediately after grading. Minimum 4 passes of a 10-tonne vibratory roller to achieve design density. Curing period: 7 days for cement binder (no traffic), 14 days for lime binder before wearing surface application. Correct compaction during this window is critical \u2014 the stabilised material has a limited workable period, and under-compaction produces a weaker base than design intent.<\/p>\n<\/div>\n<\/div>\n

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The 92 Kennametal RK4 Bits \u2014 Why Bit Specification Matters for Korean Road Material<\/h2>\n

The THOR ST’s 92 Kennametal RK4 cutting bits are not generic tungsten carbide tips \u2014 Kennametal is a globally recognised precision tooling manufacturer, and the RK4 specification designates a road milling bit designed for high-impact cutting through both compacted granular base material and stabilised or asphalt pavement material. The RK4 bit geometry combines:<\/p>\n

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Conical tip geometry<\/p>\n

The conical tip concentrates cutting force at the point of contact rather than distributing it across a flat impact face (as in agricultural THOR teeth). This concentration is essential for penetrating compacted road base material and partially consolidated asphalt without requiring the explosive impact action of the agricultural stone crusher tooth \u2014 the THOR ST produces a grinding\/milling action rather than a fracture impact action.<\/p>\n<\/div>\n

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360\u00b0 rotation capability<\/p>\n

RK4 bits are held in rotating holders that allow the bit to rotate around its axis during cutting \u2014 distributing wear evenly around the full tip circumference rather than concentrating wear on one face. This rotation capability gives RK4 bits 3\u20135 times the service life of fixed-position bits in road milling applications \u2014 a critical factor for the economics of Korean road FDR projects where bit replacement mid-project adds significant cost.<\/p>\n<\/div>\n

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Grade-specification carbide<\/p>\n

Korean rural road base material contains granite aggregate from the same geological sources that challenge the THOR 2.4 agricultural teeth. The RK4’s carbide grade is optimised for sustained cutting of this hard aggregate material at road milling speeds \u2014 combining the hardness to resist granite abrasion with the toughness to resist the impact loading from irregular base material composition.<\/p>\n<\/div>\n<\/div>\n

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Binder Selection for Korean Rural Roads \u2014 Cement, Lime, and Fly Ash<\/h2>\n

\"Korean<\/p>\n

Binder selection for Korean road FDR is determined by the existing base material type, the moisture condition at treatment, and the required bearing capacity improvement. Three binder types are used in Korean FDR applications:<\/p>\n

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Portland Cement \u2014 Highest Strength, Fast Setting<\/p>\n

Cement-stabilised FDR layers achieve the highest early and long-term bearing capacity of the three binder types \u2014 suitable for Korean agricultural roads carrying heavy harvest truck loads (15\u201325 tonne loaded GVW). Application rate: typically 3\u20136% by dry weight of treated material, confirmed by laboratory mix design for the specific base material. Cement FDR requires completion of compaction within 2\u20133 hours of mixing \u2014 the shortest workable window of the three binders. Korean highland roads with access to ready-mixed cement or bagged cement delivery are candidates for cement FDR.<\/p>\n

Working window: 2\u20133 hours. 7-day traffic restriction. Best for: high-traffic agricultural roads.<\/p>\n<\/div>\n

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Quicklime \u2014 Best for Wet or Plastic Base Material<\/p>\n

Quicklime (calcium oxide) reacts with moisture in the base material \u2014 drying the soil and modifying the clay minerals. This makes quicklime FDR the preferred choice when the existing base is wet (above optimum moisture content), plastic (soft under load), or when the base material contains significant clay or silt fractions that prevent effective cement stabilisation. The lime reaction takes 24\u201372 hours before the soil modifies sufficiently for compaction \u2014 a longer workable window than cement, but also a longer wait before final compaction can begin.<\/p>\n

Working window: 24\u201372 hours. 14-day traffic restriction. Best for: wet or clay-rich base material.<\/p>\n<\/div>\n

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Fly Ash \u2014 Supplement Binder for Modified Soil Condition<\/p>\n

Class C fly ash (from coal-fired power stations) is a pozzolanic material \u2014 it reacts with calcium from lime or cement to form cementitious products. Used as a supplement to cement or lime (not typically as a sole binder), fly ash improves workability and extends the working window while reducing the total binder cost. For Korean rural road FDR projects near coal power plant ash disposal sites (North Gyeongsang and South Chungcheong provinces), fly ash availability can reduce binder material cost significantly.<\/p>\n

Typically used as 20\u201340% supplement to cement or lime \u2014 not as standalone binder. Confirm pozzolanic activity grade for the specific ash source.<\/p>\n<\/div>\n<\/div>\n

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Korean Rural Road Categories \u2014 Where FDR Applies and Where It Does Not<\/h2>\n

Not every Korean rural road failure is appropriate for FDR with the THOR ST. Understanding which road categories and failure modes FDR addresses \u2014 and which require different solutions \u2014 prevents deployment on projects where the investment will not deliver the expected structural improvement:<\/p>\n

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FDR is appropriate:<\/p>\n