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each layer of material composing the backfill shall be not less than 95 percent of the relative maximum density as determined by the AASHTO Compacting Test T99. Each layer of backfill material which does not contain sufficient moisture to compact thoroughly shall be sprinkled and mixed with water as directed.
MATERIALS a. General. ... plate washers or AASHTO M 270 (ASTM A709) Grade 36 plate washers hot dip galvanized as per AASHTO M 111 (ASTM A123) in connections. ... Use a minimum of 2 feet of approved granular material to backfill the sides and top of the structure. When manufacturer''s recommendations require more granular material ...
Backfill General (1) Furnish materials consisting of either sandsized particles or sandsized particles mixed with gravel, crushed gravel, or crushed stone. Do not use materials classified under as crushed concrete, reclaimed asphalt, reprocessed material, and blended material. The contractor may use
The AASHTO Soil Classification System was developed by the American Association of State Highway and Transportation Officials, and is used as a guide for the classification of soils and soilaggregate mixtures for highway construction purposes. The classification system was first developed by Hogentogler and Terzaghi in 1929, but has been revised several times since.
AASHTO serves as a liaison between state departments of transportation and the Federal government. AASHTO is an international leader in setting technical standards for all phases of highway system development. Standards are issued for design, construction of highways and bridges, materials, and many other technical areas.
backfill is defined as all replaced excavation and new embankment material that is adjacent to the three sided structure, wingwalls and headwalls. backfill material within zone a must meet the material specifications of aashto soil type a1 or a3. spans less than or equal to 24'' with fill height less than 12'' may also use aashto soil type a2 or
2. The material shall meet ASTM D2488 angular or subangular classification. 3. Deleterious materials shall be limited to: a) maximum 20% reclaimed pavement materials and b) no wood, soil or organic materials are permitted 4. Material hardness – Maximum loss of 40% in the LA Abrasion test (AASHTO .
Fill and backfill adjacent to any type of structure shall not be compacted with heavy equipment; Hand operated equipment shall be used within meters of any structures. Every effort shall be made to place backfill materials symmetrically and in uniform layers to prevent unnecessary eccentric loading on a structure or foundation.
Apr 01, 2009· Structure Backfill Types The structure backfill type shall be as specified. Within each of the following structure backfill types, the Contractor shall choose from the listed options for each type: (a) Type 1 1. structure backfill in accordance with 2. nonremovable or removable flowable backfill in accordance with 213. (b) Type ...
aashto m43 notation aashto m145 no. 4 () no. 200 () ll pi cu cc i (2) crushed rock, angular 3 n/a angular crushed stone or rock, crushed gravel, crushed slag large voids with little or no fines 5, 56, 57 (4) 6, 67 class v materials shall not be permitted as bedding and backfill material. classes of embedment and backfill
OA FREQUENCY GUIDE SCHEDULE for Minimum Materials Sampling, Testing, and Inspection . CP = Colorado Procedures CPL = Colorado Procedure Laboratory, T = AASHTO Procedures, C = ASTM Procedures . CDOT Materials FormsSerialized (2017 and newer) can be located at: ... Item 206 Structure Backfill, Note on rocky material. CP 25. for 1point check ...
BACKFILL MATERIALS SELECTION OF BACKFILLL MATERIALS PROCESSING OF BACKFILL MATERIALS This course is adapted from the Unified Facilities Criteria of the United States government, which is in the public domain, is authorized for unlimited distribution, and is not copyrighted.
Carefully ram and tamp specified backfill materials under and around supports and leave in place as a guard against breakage of supported structure due to backfill settlement. No additional payment will be made for material left in place or for labor of installing and maintaining supports.
Where backfill material is being placed too close to the structure to permit compaction with blading and rolling equipment, use mechanical tamps and rammers to avoid damage to the structure. Avoid wedging action of backfill against structures. To prevent such action, .
This means the bridge structure itself and the backfill soils surrounding the structure interact with each other to support the loads. In effect, the backfill material is part of the bridge. Because of this interaction, the bridge structure is typically lighter, and there can be significant savings in structure costs. ... AASHTO (American ...
Typical specifications include better backfill materials and some level of compaction. The soil component of the pipe/soil structure provides more strength, resulting in DR18 pipe deflections of considerably less than 1%. For pipes with thinner walls (such as DR41 and DR51), backfill does become a .
Material suitable for backfill and not needed for backfill at the structure, but needed elsewhere shall be stockpiled until moved and used elsewhere. BACKFILL A. The excavation shall then be brought to the structures bottom elevation by placing and compacting 6inch layers of Oolitic limerock (or material previously defined) to 95 percent of
method in use. Backfill material shall be approved by the Engineer. Special care shall be taken in placing the backfill. Great care shall be used to obtain thorough compaction under the haunches and along the sides to the top of the pipe. The backfill shall be placed in loose layers not exceeding 6 inches (150 mm) in depth under and around the
may control the type of material to be used at a site, and a specific design for each type of material available is necessary. Pipe Arches. Pipe arches, sometimes referred to as "squash pipe," are circular culverts that have been reshaped into a structure with .
About Basic Materials for Highway and Structure Construction. Aggregates are used in a variety of ways in highway construction, as shouldering material, bases, and of course, as an ingredient in the production of HMA and PCC. Both HMA and PCC are used for surfaces and patching on highways.
A. Selected backfill shall be of a quality acceptable to the Engineer and shall consist of suitable material from the excavation complying to Table 1. It shall be free from sod, frozen earth, organic materials, rubbish, or debris. If the material does not comply with Table .
foundation material as required by T99 or T180. If Class 1 structural backfill material is used, the minimum moisture shall not be lower than two (2) percentage points under optimum moisture at 95% compaction as determined by AASHTO T180 modified, tested at random through the depth of the fill. .. . Inspection of Forms and Falsework a.
Structure backfill shall have a minimum resistivity of 3000 Ω cm at 20 saturation when tested in accordance with AASHTO T 288. The pH of the backfill material shall be in the range of 5 to 10 as determined in accordance with AASHTO T 289. The maximum soluble salt content of the backfill material shall not exceed
(B) Structure Backfill Material B. When tested according to AASHTO T 176, the sand equivalent value of the backfill material shall be equal to or greater than the surrounding soil. Structure fill or backfill material placed behind bridge abutments, wingwalls and retaining walls shall be structure backfill material A.
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