1. 1.1 STEEL REINFORCEMENT GENERAL FABRICATION AND PLACEMENT OF REINFORCEMENT. a. This section shall apply to round bars 19 mm or smaller in diameter with strength of SR 235 to SR 295 and deformed bars D41 or smaller in nominal diameter with strength of SD 295 to SD 390. Fabrication and placement of reinforcement of types, diameters and strength levels not covered by this section shall be as specified in the Special Provisions. b. The bar types, diameters scope of applications, as well as the number, shapes and dimensions of bars shall be as specified in the Special Provisions. All longitudinal bars shall be deformed bars. c. The types and diameters of weld mesh and reinforcement grid shall be in accordance with the Special Provision. d. Splicing of reinforcement shall be lap slices, gas pressure welding splices or special splices and shall be in accordance with the Special Provisions. Unless specified in the Special Provisions, the Contractor shall determine the method of splicing subject to approval by the Architect/Engineer. Deformed bars with a diameter D35 or larger shall as a rule have no lap splices. e. Reinforcement bars shall site-assembled or preassembled and shall be placed in accordance with the Special Provisions. Unless specified in the Special Provisions, the Contractor shall determine the placement method subject to approval by the Architect/Engineer. f. The Contractor shall formulate a construction plan and shop drawings based on the Special Provisions and submit them to the Architect/Engineer for approval. 1.2 a. Reinforcing bars to be used shall conform to JIS G 3112 (Steel REINFORCING Bars for Reinforced Concrete Structures) BARS AND WELD MESH b. Weld mesh and reinforcement grid shall conform to JIS G 3551 (Weld Mesh and Reinforcement Grid). a. Deleteriously bent or defective bars shall not be used. b. Reinforcing bars in coils shall be used after passing through a straightener. Bars shall not be damaged during the straightening process. FABRICATION OF REINFORCEMENT 1.3 1 of 12 floor 20. 2. 2004). beans. The desired strengths of concrete for various parts of the project have been shown on the drawing.0% or less and sand with a chloride content between 0.1% may be used in accordance with the Special Provisions. provided that the concrete containing such aggregates is proven to possess the specified qualities.4g/cm3 or larger and a water absorption of 4. Aggregates for normal concrete shall conform standard specification to JASS AGGREGATES 5 Section 4.25. gravel and sand with an oven-dry density of 2.1 and 2.40 Recycled aggregate 20. However. and unreinforced concrete work. PORTLAND All cement shall be ordinary Portland Cement confirming to the requirements CEMENT of JIS R 5210 (Portland Cement).4 Cement shall conform to the Standard specifications.25 slabs.2.04% and 0. 2. 20 mm or 15 GRADING 2. 2 of 12 . SCOPE including reinforced work for such structure as steel-framed reinforcement concrete structures.25.25 20. Concrete work shall conform to all requirements of building works with SPECIFICATIONS Japanese Architectural Standard specification (JASS 5.6 Aggregates for reinforced concrete should comply with JISS 5. The maximum size of course aggregate shall be 25 mm. walls Foundations 20.40 Normal-weight aggregate shall be in accordance with (1) through (3) below: Gravel and sand shall possess the qualities specified in Tables 2. Concrete shall be composed of Portland cement.1 CONCRETE PLAIN AND REINFORCED This specification shall apply to cast-in-place reinforce concrete work.2. Table 2.25 Columns.5 2. The concrete mixtures will be designed by the engineer who will determine the required quality of the concrete for the structures covered by these specifications. The maximum size of course aggregate is given in following Table.3 2. blast-furnace slag coarse aggregate 20 20.1 Maximum size of Course Aggregate Classified by Member Group (mm) Member Gravel Crushed stone. mm.2 2. 2004. as provided here under. water fine and coarse COMPOSITION aggregate and any admixtures as and when specified. (Concrete Material). 3 of 12 .5 ≤ 3. (2) or (3) above.5 ≤ 3. and slag aggregate shall conform to JIS A 5011 (Slag Aggregate for Concrete).5 ≤ 1.” d.15-mm sieve shall be 15%. mm) 40mm 25mm 20mm 50 100 40 95100 30 10 0 25 9510 0 10 0 20 3570 90100 15 3070 10 1030 2055 100 5 0-5 010 010 90100 2. When chemical or physical unsoundness of aggregate is suspected. However.0% in weight of the grains that float in the liquid of the density of 1. durability.2 Volume lost by wash test (%) ≤ 1.2 and 4. strength.0 Organic impurities Lighter in color than standard solution or sample color Chlorides (NaCl) equivalent (%) - Sand ≥ 2.3. f.0 ≤ 0.04(1) Note: (1) ≤ 0.15 - Sand Note: (1) When using combinations of crushed sand and slag sand.2 and 2. the percentage passing a 0.5 0-5 0-5 8010 0 5090 1. size.2 Quality of Gravel and Sand Oven-dry Water specific Type absorption density (%) (g/cm3) Gravel ≥ 2. each aggregate shall meet the quality requirements before blending specified in (1).0 ≤ 3. by mass (%) Nominal Sieve size (mm) Gravel (Max. (2) Crushed stone and crushed sand shall conform to JIS A 5005 (Crushed Stone and Crushed Sand for Concrete). (4) When using combinations of different types of aggregates.Table 2. Young’s modulus. e. the use of it and method of use shall be subject to approval by the Architect/Engineer. Aggregates for concrete portions requiring exceptionally high fire resistance shall be in accordance with the Special Provisions.6 -2565 1035 0. Specified mixture proportions of concrete shall be determined to provide PROPORTION the required workability. Lightweight aggregates shall be in accordance with Section 16 “Lightweight Concrete.0 Clay lumps (%) ≤ 0. (3) Recycled aggregates shall conform to Table 4.3 after blending.95(g/cm3). the chloride content and grading shall meet the requirements of Tables 2. and shall contain not more than 1. 2.02 (%) for the “long-term” planned service life class.3 Standard Grading of Gravel and Sand Percentage passing each sieve.3 210(1) 0.2 0.7 MIX a. respectively. Table 2. 2) PROPORTIONING STRENGTH (2) Where the age for strength control of concrete in structure is n days (28<n ≤91). T and Tn shall be in accordance with (1) and (2) below.3) and (5. F = proportioning strength of concrete (N/mm2) Fq= quality standard strength of concrete (N/mm2) T = correction value for concrete strength according to the anticipated mean air temperature where the age for strength control is 28 days (N/mm2) Tn= correction value for concrete strength according to the anticipated mean air temperature where the age for strength control is n days (28<n ≤91) (N/mm2). However. The age for strength control of concrete in structure shall be within 91 days and as specified in the Special Provisions. the method shall be water curing under field conditions or standard curing when the designated age for strength control is 28 days and seal curing under field conditions when the designated age is older than 28 days. (1) Where the age for strength control of concrete in structure is 28 days. Correction values of concrete strength in terms of anticipated mean air temperature. (5. d.4) Where. F = Fq + T + 1. F = Fq + Tn + 1. 2.2). σ = standard deviation of concrete strength (N/mm2). The curing method of control specimens for the strength of concrete in structure shall be in accordance with the Special Provisions. b.8 a. (5. the proportioning strength shall be the larger of the values calculated by Eqs.1) (5.73 σ (N/mm2) F = 0. the trail mixing process may be omitted.73 σ (N/mm2) F = 0. it shall be 28 days.b. when JIS A 5308 – conformed ready-mixed concrete is to be employed. Specified mixture proportions shall as a rule is established on the basis of trail mixtures. Unless specified in the Special Provisions.1) and (5. Proportioning strength shall be expressed as the 28-days old compressive strength of standard-cured specimens.3) (5.85 (Fq + T) = 3 σ (N/mm2) (5. and shall be in accordance with (1) or (2) below depending on the designated age for strength control of concrete in structure. 4 of 12 .85 (Fq +Tn) = 3 σ (N/mm2) (5.4). Unless specified in the Special Provisions. c. the proportioning strength shall be the larger of the values calculated by Eqs. the slump of lightweight concrete. Where cement other than those indicated in table 5. Tn shall be as specified in the Special Provisions. t. Table 5. However. (2) Tn shall be determined using Table 5. The standard deviation of the strength of concrete employed.2 according to the type of cement and anticipated mean air temperature range. it shall be the larger of 2.1 according to the type of cement and anticipated mean air temperature range. σ shall be established based on records at the ready-mixed concrete plant. 5 of 12 .respectively: (1) T shall be determined using Table 5. T shall be as specified in the Special Provisions. Where no WORKABILITY record is available. 18.1 Standard Values of Correction Value T for concrete Strength Range of anticipated mean air temperature.5 N/mm2 and 0. Type of cement during 28 days after concrete placement (˚C) Normal Portland ≥ 16 8 ≤ t < 16 3≤t<8 Cement Correction value T for concrete strength in terms of air 0 3 6 temperature (N/mm2). high strength concrete. mass concrete and concrete placed underwater shall be in accordance with Sections 16.1 is employed. It shall be 18 cm at the highest for concrete with a quality standard strength of less than 33 N/mm2.1 Fq.2 Standard Values of Correction Value Tn for Concrete Strength Age n Range of anticipated mean air Type of cement (days) temperature.2 is employed. respectively. plasticized concrete.9 c. Table 5. 19. The slump of concrete with a quality standard strength of 33 N/mm2 or higher shall be 21 cm at the highest. AND SLUMP a. 17. Where cement other than those indicated in Table 5. 22 and 25. during 28 days after concrete placement 42 ≥8 4≤t<8 2≤t<4 Normal Portland 56 ≥4 2≤t<4 cement 91 ≥2 Correction value Tn for concrete strength in terms of 0 3 6 air temperature (N/mm2) 2. The workability of concrete shall be such that the concrete can be placed densely in all corners of forms and around reinforcing bars with minimum bleeding and segregation under the conditions of portions to be placed and methods of deposition compaction to be employed. b. t. high fluidity concrete. Water-cement ratio (%) 65 Portland cement Type A Portland blast-furnace slag cement Type A Portland fly-ash cement Type A Portland pozzolan cement Type B Portland blast-furnace slag cement Type B Portland fly-ash cement Type B Portland pozzolan cement 60 b.3 Type of cement (1) Maximum water-cement Ratios Max.5.10 WATER-CEMENT RATIO a. CEMENT CONTENT a. The cement content shall be at least 270 kg/m3. the maximum watercement ratio shall be as specified in the Special Provisions. At construction joints. it shall be 4.4 and unit water content in 5. b. concrete shall be deposited as near as practicable to its final position. Care shall be exercised to prevent concrete from staining surfaces of reinforcement. For cements other than those indicated in Table 5. 2.2. Table 5. airentraining and water-reducing admixture or air-entraining and high-range water-reducing admixture shall be as specified in the Special Provisions. d. concrete shall be placed and compacted with care to leave no unsound portion near the joints due to inadequate compaction or concentration of bleeding water.12 AIR CONTENT The air content of concrete containing an air-entraining admixture. 2. e. The cement content shall be not less than the values calculated from the water-cement ratio in 5.3.11 The water-cement ratio shall be a value necessary for attaining the proportioning strength but not more than the maximum value specified in “a” above. b. c. Concrete shall be placed continuously to achieve monolithic concrete in a section for which one sequence of concrete placing is planned. In placing. The rate of placing shall be in the range of allowing efficient compaction depending on the workability of concrete and construction conditions of the relevant portions. Unless specified in the Special Provisions.5%. The maximum water-cement ratio shall be as specified in Table 5. formwork and preset tile that are out of the concreting section being placed. 2.13 PLACING a. The free-fall height in placing concrete shall be limited to a range in 6 of 12 .3. 2.16 MOIST CURING Concrete after placement shall be moist-cured by being covered with sheathing with low water permeability. form vibrators or tamping rods shall be used for compaction. Internal vibrators. fogging. forms. d. subject to approval by the Architect/Engineer. Other tools shall be used as auxiliary equipment where necessary. moist curing may be terminated even before the completion of the moist curing period specified in “a” above.which no segregation of concrete occurs. f.14 COMPACTION a. and vibrating shall be continued until cement paste rises to the concrete surface. rapid temperature changes. or by water spraying. Internal vibrators shall be used on each fresh layer of concrete and inserted vertically to a depth so that the tips of vibrators penetrate the top level of the previously placed layer of concrete. 7 of 12 .2. Form vibrators shall be vibrated systematically according to the depth and rate of concrete placing so that dense concrete can be achieved. 2. Table 8. CURING 2. b. The distance between insertions of vibrators shall be not more than 60 cm. if it is confirmed that the compressive strength of the concrete* meets the requirements of Table 8. Spacers or steel bar supports shall be corrected before placing concrete to ensure proper cover depth. Concrete shall be compacted around reinforcement and embedded metals and into corners of the forms so that dense concrete can be obtained. The curing period shall be in accordance with Table 8. c.15 Beginning immediately after placement. or application of a curing compound. Displacement of steel bars. concrete shall be protected from rapid drying excessively hot or cold temperatures. curing mats or watertight sheeting.1 according to planned service life classes. vibration and external forces for the period necessary for sufficient hydration of the cement and hardening of he concrete. g.1 Moist Curing Period Planned service life class General/Standard ≥ 3 days ≥ 5 days ≥ 7 days Cement type High-early-strength Portland cement Normal Portland cement Other cements Long-term ≥ 5 days ≥ 7 days ≥ 10 days For concrete members 18 cm or more in thickness made using high-early strength Portland cement or normal Portland cement. The time limit for intervals between placing operations shall be determined in the range of causing no cold joints. contact with walls. Unless specified in the Special Provisions or Design Documents.9 but before the period specified in “a” above or before the concrete attains the compressive strength specified in “b” above. Table 10.2 Compressive Strength of Concrete Required for Terminating Moist Curing (N/mm2) Planned service life class General/Standard Long-term ≥ 10 ≥ 15 Cement type High-early-strength Portland cement Normal Portland cement a. the minimum cover depth shall be the values given in Table 10.1. (2) For lightweight concrete.17 b. these values shall be increased by 10 mm. risers of continuous 50(2) the ground footing Foundations. Under high air temperature.[Note] * This should be carried out in accordance with JASS 5 T-603 (Method of Test for Compressive Strength for Estimating Strength of Concrete in Structure). DESIGN DEPTH a. nonbearing Outdoor 30 40 with the walls ground Columns. strong wind or direct sunlight. Table 8. Indoor 40 40 bearing walls Outdoor 40 50 Retaining walls 50 50 Portion in Columns. the cover depth and corrosion-inhibiting treatment for diagonal bars placed at corners and openings of buildings to control cracking shall be as specified in the Special Provisions or Design documents. roof Indoor 30 30 in contact slabs. Unless specified in the Special Provisions or Design Documents. The curing method should be the same as that for control specimens for concrete in structure.1 and shall be specified in the Design Documents or Special Provisions.1. floor slabs. the exposed surfaces of concrete shall be kept moist by spraying water. beams. retaining walls 70(2) Note: (1) This refers to finishing effective in increasing durability. The design cover depth shall not be less than the values given in Table 10. COVER b. 2.1 Standard Values of Design Cover Depth Design Cover Depth Portion With finishing(1) Without finishing Portions not Floor slabs. 8 of 12 . the design cover depth shall be as specified in Table 10. curing shall be controlled to avoid rapid drying of the concrete surfaces. fogging or other appropriate methods until the end of the specified period or until the specified compressive strength is attained. When sheathing is to be removed after the period of retaining sheathing specified in 12. beam. Where effective measures against reinforcement corrosion are taken. 9 of 12 . 5. but for reference a typical detail provide in Annexure A. The applicable requirements of this Section shall apply to all GENERAL Structural Steel Work under this specification. Bolts 10 of 12 3. Standard No. Except as otherwise indicated on the Drawings or specified BOLTS.4.4 3.3. Except as otherwise shown on the Drawings. fabricating and installing and painting metal not otherwise specified under other Sections of the Specifications. STRUCTURAL E-60 or E-70 series electrodes shall be used. Structural steel specification for building constructions. . fabrication.1 STRUCTURAL STEEL (JASS 6 1993) This Section covers general requirements for structural steel SCOPE work. NUTS AND herein. JIS Z 3211 JIS Z 3212 JIS Z 3214 JIS Z 3351 JIS Z 3352 JIS Z 3312 JIS Z 3315 JIS Z 3313 Title Covered electrodes for mild steel Covered electrodes for high strength steel Covered electrodes for atmospheric corrosion resisting steel Submerged are welding fluxes for carbon steel and low alloy steel Submerged are welding fluxes for carbon steel and high strength steel MAG welding solid wires for mild steel and high strength steel Solid wire for CO2 gas shielded are welding of atmospheric corrosion resisting steel Are welding flux cored wires for mild steel and high strength steel 3.1 Welding rod for manual welding of structural carbon steels. Structural steel shall conform to the requirement of STRUCTURAL JAPANESE ARCHITECTURAL STANDARDS STEEL SPECIFICATION (JASS 6 1993). 3. methods and precautions for erection of steel structures and other miscellaneous general requirements to construction work in which structural steel is used for main structural members of buildings or structure.3. For High. 3.WELDING ROD strength low alloy steels E-70 series Low Hydrogen Electrodes shall be used. This Section also covers furnishing.2. welding material WELDING shall conform the standard specification for class of base MATERIAL metal sizes and building conditions for standard shown in table. bolts and nuts shall conform the requirements of AIJ WASHERS Structure Steel Standard Specifications for Carbon Steel Externally and Internally Threaded Standard Fasteners. The different shapes of angles and their dimensions are provided in JASS 6 1993 Code. 3. 5. ii) Temporary anticorrosive paint to prevent stains due to rust general during the construction period shall comply with the special notes. 3.shall be Grade A for general application. DOOR structural steel supports. Anchor bolts shall be of diameter as shown hooked or eyed as required and provided with sleeve nuts and double nuts as shown. Therefore.9 Steel stairs Steel ladders Fixed or removable railing Embedded steel anchors/fasteners. channels or girders being used shall conform to FABRICATING the above mentioned specifications. STAIRS.000m2. The classification and scope of paint shall comply with the special notes. Nuts shall be 4T of JIS B 1180 and 4T of JIS B 1181 of similar material. stairs.5. 4.1 The Building Standards Law prescribes that hexagon bolt HEXAGON BOLT fastening cannot be generally applied except for structures with maximum eaves height of not more than 9m. 2.7 structural steel.6 3. i) This part concerns anticorrosive paint on steel frames to give them long-term rust resistance. The angles. more than exactly required. door frames and windows etc STEEL TRUSSES. All sections to be used in fabrication shall be of correct cut-lengths. not to produce any extra tension in the members due to shortening or increase in cut-lengths. handrail supports and other FRAMES AND fastenings shall be furnished and installed in accordance WINDOWS ETC 11 of 12 . Miscellaneous work required in ANTICORROSIVE PAINT 3.8 The work covered by this Clause includes furnishing and MISCELLANEOUS installing miscellaneous structural steel work including METAL the following: 1. 3. 3. Structural steel trusses. Screw anchor devices for setting in concrete to permit withdrawal of anchor bolts after concrete have set. complete with stringers. with square or hexagon heads. grating treads and landings. finish class of fit and thread series as their companion bolts and shall be washer-faced except as otherwise indicated or specified. hexagon bolt fastening is limited to relatively insignificant structures. span of not more than 13m and total floor area of not more than 3. 3. 10 12 of 12 .9.1 All material for steel trusses. All Steel fabrications shall be in a first class workmanlike INSTALLATION manner. except as otherwise shown.with the details. The embedded metalwork to be furnished and installed under EMBEDDED this Clause shall include anchor bolts. Field connections shall be made as indicated on the Drawings. and METALWORK other metal work required for installation. The embedded metal work shall be of materials and standards specified on the Drawings. 3. anchor bars. 3. stairs. Before placing concrete care shall be taken to determine that all embedded items are firmly and securely fastened. sizes and dimensions. door frames and windows MATERIAL etc. shall be steel conforming to JASS 6 (1993) Specifications for Structural Steel work for building constructions.9. and at the locations shown on the Drawings.2 3. The units shall be shop assembled and fabricated in sub-assemblies for convenient installation.