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233 IBRACON Structures and Materials Journal • 2013 • vol. 6 • nº 2
A. C. MARQUES | T. N. BITTENCOURT | M. P. BARBOSA
of 16% and 10%, respectively, between the results concerning a
365 days period. The decrease in the compliance function value
for specimens loaded later was expected since their degree of hy-
dration is higher and they have less available water (fact reported
by Neville [4]). This behavior was also experimentally obtained
by Equipe de FURNAS [3], Kalintzis [22], Takeuti [23], and oth-
ers. The proximity among the compliance function values for the
specimens kept outside the chamber was due to the higher relative
humidity for the loading at 14 days (68%), which decreased the
compliance function value to this age.
Besides the comparison between experimental results, they were
also compared to some prediction models available in the literature
The compliance function from experimental and prediction models
results are shown in Figures 7, 8, 9, and 10. In Figure 7 is shown
the compliance function from experimental results regarding the
first age at loading (14 days) for specimens kept inside the cham-
ber, compared to the compliance function for the prediction mod-
els. In Figure 8 is shown the comparison made between the experi-
mental compliance function and the predicted ones for specimens
loaded at 14 days and kept outside the chamber.
As can be seen at Figures 7 and 8, several prediction models are
close to experimental results. The comparison among the experi-
mental and the prediction models results is made by using the co-
efficient of variation (wB3).
As prediction models do not consider the variation of the relative
humidity over time, it was set as input the mean relative humidity
for the first month of the test. The table 6 shows the input data used
for each prediction model.
The same comparison with the prediction models and the results
inside and outside the chamber was made for the specimens load-
ed at 49 days. In Figures 9 and 10 are shown respectively the
curves of experimental compliance function and of the prediction
models for the specimens kept inside and outside the chamber.
The table 7 shows the coefficient of variation (wB3) obtained for
all prediction models regarding each load age and environmental
condition. It is also shown the overall coefficient of variation of the
deviations of the models proposed by Bažant and Baweja [16].
Considering acceptable error values up to 25% for wB3 coefficient, it
can be seen at Table 7 that, although some prediction models can-
not predict the behavior of the specimens load at 49 days and kept
inside the chamber, in general all prediction models are suitable.
Among the analyzed models, it was observed that most of them
presents good prediction compared to the experimental results
(wB3 approximately 18%). However, more comparisons among
the prediction models and experimental results from different SCC
mixtures varying the type and amount of cement and types of ag-
gregates are necessary, in order to corroborate if those prediction
models can be used for SCC’s.
4. Conclusions
From the experimental and prediction model results it can be seen that:
n Regarding the fresh SCC tests, all results were within the limits
set by the Brazilian standard code. The concrete used is clas-
sified as SF1, VS2, VF2 and PL2;
n It was found that the variation of humidity during the first month
test is significant for the drying creep test. This interference is
attributed to the greater availability of water movement in the
early ages;
n Specimens loaded at 49 days presented lower results for com-
pliance function. This is due to the higher degree of hydration
of the concrete at the age of 49 days and less available water.
n All the studied prediction models could predict the creep of the
analyzed SCC. Among the used prediction models, most of
them showed a wB3 coefficients about 18%;
n It is still necessary to perform creep tests with different SCC
Figure 9 – Comparison among experimental
and prediction model results for
specimens kept inside the climated-controlled
chamber and age at loading of 49 days
Figure 10 – Comparison among experimental
and prediction model results for specimens
kept outside the climated-controlled
chamber and age at loading of 49 days