Summary Report of Experimental Study on Dehydration Crack Appearing in the Construction of Turpan Civil Airport Cement Concrete Pavement - The Issues and Discussion of Modern Concrete Science - page 234

Fig. 16.22 At 10:58, nearby
slab which employed
troweling machine was
entirely wet, while almost half
of the slab which was treated
by napping far away was
permeated to dry

At 10:58, it could be seen that nearby slab which employed troweling machine
was still wet, while almost half of the slab which was treated by napping far away
was permeated to dry, as shown in Fig. 16.22 .
As shown in Figure 16.21 , soaking was started at 10:56.
At 11:02, it can be signi

cantly seen that permeating speed at napped section
exceeded permeating speed at troweling machine utilization section, as shown in
Fig. 16.23 .
Water on two slabs in napping section penetrated into concrete entirely at 11:03
(dried by sunlight).
Water on slab in troweling machine utilization section permeated into slab
entirely at 10:53 (basically dried by sunlight).
The experimental

results demonstrated that permeating time at troweling

machine section was 5 7 min longer than permeating time at napped section, which

indicated that utilization of troweling machine improved permeability and frost
resistance of concrete and strengthened concrete durability.

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16.3.6 Experiment on Water-to-Cement Ratio (W/C)

During the experimental process, we found that water demand of concrete which
employed fiber was higher under the same workability. That is to say, in the same
condition, larger W/C was needed for concrete which employed ber to meet

similar construction technology. In order to verify how many W/C was needed to
increase, compassion experiment was carried out at construction

field on August 23.

Experimental process was as follows.
The date was August 23, 2009. Locale was third at Turpan airport. Comparison
speci cs of parameter and construction technology of concrete which employed