Full Scale Load Testing BPEX Project, Maptaphut Rayong

The maximum deflection at midspan was found to be within the limit of L 2 /20000h =4.5 mm according to ACI 318‐08. Therefore, the beam is considered satisfactory forthe load test and the recovery rate need not be checked.Nonetheless, the maximum recovery at midspan is 0.66 mm, which is 24.5% of themaximum deflection. This recovery rate is also smaller than the limit of 25%required by ACI 318‐08. Thus, the beam is also considered satisfactory using therecovery rate criteria.Note that a member that has maximum deflection below the limit of L 2 /20000h isconsidered very stiff by ACI. This limit is much more stringent than the limit ofmaximum deflection under live load of L/360 = 25 mm.Figure 15 shows the deflection at column support, 1/3 of the span, and at midspanof the test beam at different loading stages. The gage for column was installed onthe tension side due to space constraints. During the initial loading, the deflectionmeasured at the column increased because the bending of the column has greatereffect than the shortening of the column. However, after sustaining the full test loadfor 24 hours, negative (shortened) value was observed.The recoveries of the members were almost immediate as very little change in theinitial and 24 hours recovery was observed. However, some small residualdeformations were observed, especially at midspan due to additional crackings ofthe member during the application of test loads.0.50.0Deflection (mm)‐0.5‐1.0‐1.5‐2.0‐2.5Full Test LoadFull Test Load after 24 HoursInitial Recovery24 Hours Recovery‐3.0Column 1/3 Span MidspanPositionFIGURE 15. DISPLACEMENT AT VARIOUS POSITIONS DURING THE TEST16