PSI - Issue 42

Stanislav Seitl et al. / Procedia Structural Integrity 42 (2022) 1512–1519 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

1514

3

2. Materials and sample preparation Four different concrete mixtures were prepared for these tests. The concrete was designed with constant cement content and different water to cement ratio. Ordinary Portland cement CEM I 42.5 R (EN 197) produced in the cement plant Hranice, Czech Republic was used. Commercial polycarboxylether superplasticizer, tap water and commonly produced aggregates - sand 0/4 (Tovacov quarry) and crushed granite aggregates (Litice nad Orlici quarry) were also used. The cement paste was prepared at three w / c ratios, namely 0.3, 0.4 and 0.5, The detailed composition for each sample is shown in Table 1. The ambient temperature of 20 ±2 °C was kept during the sample preparation. Concretes were mixed in a laboratory mixer; the volume of each batch was 20 litters. After mixing, the concrete was placed into steel moulds. The moulds with concrete were covered with Polyethylene (PE) sheet. After demoulding at the age of 22-24 hours, specimens were enveloped with PE-foil for avoiding of water exchange with environment. In Figs. 1 and 2, the typical concrete structures are mentioned for different maximum size of aggregates D max = 8 mm and D max = 16 mm, respectively.

Table 1.: Composition of mixtures per 1 m 3 and dates of its preparation ĂƚĞ ŽĨ ƉƌĞƉĂƌĂƚŝŽŶ Ϯϴ͘ϭ͘ϮϬϮϭ ϵ͘Ϯ͘ϮϬϮϭ

ϭϲ͘Ϯ͘ϮϬϮϭ

ϰ͘ϱ͘ϮϬϮϭ

tĂƚĞƌ ƚŽ ĐĞŵĞŶƚ ƌĂƚŝŽ Ͳ ǁ ͬ Đ

Ϭ͘ϱϬ

Ϭ͘ϰϬ

Ϭ͘ϯϬ

Ϭ͘ϯϬ

DĂdžŝŵƵŵ ƐŝnjĞ ŽĨ ĂŐŐƌĞŐĂƚĞƐ Ͳ ŵĂdž

΀ŵŵ΁

ϴ

ϴ

ϴ

ϭϲ

D / ϰϮ͘ϱ Z

΀ŬŐ΁ ΀ŬŐ΁ ΀ŬŐ΁ ΀ŬŐ΁ ΀ŬŐ΁ ΀ŬŐ΁

ϰϱϬ ϮϮϱ ϭ͘ϱ ϵϵϬ ϳϬϬ

ϰϱϬ ϭϴϬ ϲ͘Ϭ

ϰϱϬ ϭϯϱ ϵ͘Ϭ

ϰϱϬ ϭϯϱ ϵ͘Ϭ ϲϱϬ

E ĨĨĞĐƚŝǀĞ ǁĂƚĞƌ S ƵƉĞƌƉůĂƐƚŝĐŝnjĞƌ S ĂŶĚ Ϭͬϰ ŵŵ

ϭϬϱϬ

ϭϭϭϬ

C ƌƵƐŚĞĚ ĂŐŐƌĞŐĂƚĞƐ ϰͬϴ ŵŵ C ƌƵƐŚĞĚ ĂŐŐƌĞŐĂƚĞƐ ϴͬϭϲ ŵŵ

ϳϰϬ

ϳϴϱ

Ϭ

Ϭ

Ϭ

Ϭ

ϭϮϰϱ

&ŝŐ͘ ϭ͘ džĂŵƉůĞ ŽĨ ĐŽŶĐƌĞƚĞ ƐƚƌƵĐƚƵƌĞ ŝŶ ĐƌŽƐƐ ƐĞĐƚŝŽŶ ϴϬ ŵŵ п ϴϬ ŵŵ ǁŝƚŚ ŵĂdžŝŵƵŵ ƐŝnjĞ ŽĨ ĂŐŐƌĞŐĂƚĞƐ Ͳ ŵĂdž = ϴ ŵŵ͘

&ŝŐ͘ Ϯ͘ džĂŵƉůĞ ŽĨ ĐŽŶĐƌĞƚĞ ƐƚƌƵĐƚƵƌĞ ŝŶ ĐƌŽƐƐ ƐĞĐƚŝŽŶ ϴϬ ŵŵ п ϴϬ ŵŵ ǁŝƚŚ ŵĂdžŝŵƵŵ ƐŝnjĞ ŽĨ ĂŐŐƌĞŐĂƚĞƐ Ͳ ŵĂdž = ϭϲ ŵŵ͘