AMENDMENT TO IRC:112-2011Amendment No. 1/IRC:112-2011/January, 2015 IRC:112-2011 “Code of Practice for Concrete Road Bridges” S. No. Clause No. & Page No. For Read 1. 6.4.2.7(1) (Page 46) Creep of concrete depends, on the stress in the concrete, age at loading and duration of loading in addition to the factors listed in Clause 6.4.2.6(1). As long as the stress in concrete does not exceed 0.36 fck creep may be assumed to be proportional to the stress. Creep of concrete depends, on the stress in the concrete, age at loading and duration of loading in addition to the factors listed in Clause 6.4.2.6(1). As long as the stress in concrete does not exceed 0.36 fcm (t0) creep may be assumed to be proportional to the stress. 2. 6.4.2.7(2) (Page 47) The values given in Table 6.9 can be considered as final creep co-efficient for design for normal weight concrete, subject to condition that the compressive stress does not exceed 0.36 fck at the age of loading and mean temperature of concrete is between 10ºC and 20ºC with seasonal variation between – 20ºC to 40ºC. For temperature greater than 40ºC the coefficient given may be increased by 10 percent in absence of accurate data. In case the compressive stress exceeds 0.36 fck, at loading, non-linear creep shall be considered. The values given in Table 6.9 can be considered as final creep co-efficient for design for normal weight concrete, subject to condition that the compressive stress does not exceed 0.36 fcm at the age of loading and mean temperature of concrete is between 10ºC and 20ºC with seasonal variation between – 20ºC to 40ºC. For temperature greater than 40ºC the co-efficient given may be increased by 10 percent in absence of accurate data. In case the compressive stress exceeds 0.36 fcm (t0), at loading, non-linear creep shall be considered. 3. Table No. 11.1 Note : Positional restraints are given for directions at Notes : right angles to the member 1. Positional restraints are given for directions at right angles to the member. 2. Cases 1 to 5 shows superstructure held in position which means the deck is held in position at some location other than the pier under consideration (say typically either at another pier or at the abutment). 3. In case of any floating deck on elastomeric bearings (simply supported or continuous), Case 7 will be applicable. 4. For a continuous deck fixed at any pier/abutment, Case 7 applies for the design of fixed pier/ abutment. For design of other piers in the longitudinal direction, Case 4 applies for piers with elastomeric bearings and Case 5 applies for piers with free metallic bearings. Note below Table (Page 114) 4. 11.3.2.2(1) (Page 115) Add at the end of the Clause. The effect of imperfection may be represented by an eccentricity in mm, limited to 50 mm lo is the height of pier in mm. INDIAN HIGHWAYS, MAY 2015 31 2.4. to) is the linear creep coefficient. Errata No. & Page No. 6.2 and 6.6.1(2) (Page 120) Where compressive stress in concrete under quasi-permanent loads is within 0. Clause No.36fck. 3. non-linear creep shall be considered.36fck.4) may be used.3. creep may be taken into account by modifying all strain values in the concrete stress-strain diagram using effective E value as per Clause 6. For splicing of bars in beams and columns the stirrups or links provided for other considerations can be taken into account to satisfy the requirement of (b) and their spacing shall not exceed 150 mm. 1/ IRC:112-2011/January. stress – Annexure (A2. n1 = 1 and n2 = 2 n1 = 2 and n2 = 2 5. The value of the standard deviation to be used for early age is required to be established by testing at least 30 numbers of samples at site.2.5.1(4) Last line (Page 115) In the absence of more refined models. kσ = 6. for which Annexure A-2 may be referred. longitudinal c is the clear cover to the longitudinal reinforcement.5.4(3) Under Eq.645 x (standard deviation for the grade of concrete). 6.36fcm(t0).1 (10) Fig 15. Wherever the clear cover exceeds 50 mm a value of 50 mm shall be used in the calculation. 4.1(3) First line (Page 115) Stress – strain relationships for concrete given in In so far as material non-linearity is concerned. non-linear creep shall be considered. For Read 1.2.1(3) (d) Last line (Page 156) For splicing of bars in beams and columns the stirrups or links provided for other considerations can be taken into account to satisfy the requirement of (2) and its spacing shall not exceed 150 mm.4. The values thus obtained should be reduced by 1.9 (Page 127) c is the clear reinforcement. No. 11. linear creep may be assumed.2.2 and 6. In case compressive stress exceeds 0. 6. unless it is know from past experience. 15. Where compressive stress in concrete under quasi-permanent loads is within 0.36 fcm(to) < σc ≤ 0. 11.2(3) (Page 39) To avoid irreversible damage like local cracking (eg.4 (iii).36 fcm(t0).AMENDMENT/ERRATA TO IRC:112-2011 S. In case compressive stress exceeds 0. 15. 12. To avoid irreversible damage like local cracking (eg.2. & Page No.48fcm(to) the non-linearity of creep may be taken into account using the following equation: ϕσ (t. creep may be taken into account by modifying all strain values in the concrete stress-strain diagram using effective E value as per Clause 6. and for steel given in Section 6 (Fig. to) is the non-linear creep coefficient.6 (under RHS sketch) (Page 160) 32 INDIAN HIGHWAYS.7) and for steel given in Section 6 strain relationships for concrete given in Annexure A2-7 (Fig. 2. ϕ (t.3. Clause No.4) may be used. 12. Refer Section 18 for details. MAY 2015 .5. linear creep may be assumed. cover to the is the strength ratio.5(4) (iii). Refer Section 18 for details.3. due to early age prestressing) the achievement of early age strength shall be verified by testing.2. For stress level in the range of 0.4. 2015 IRC:112-2011 “Code of Practice for Concrete Road Bridges” S. For Read 5. due to early age prestressing) the achievement of early age strength shall be verified by testing. In the absence of more refined models. 12. It is to be noted that the field testing results based on small number of samples are a measure of the mean value of early age strength and not of the characteristic value of early age. No.