Durability test results for air entrained concrete samples after 200 cycles freezing and thawing:
(1 cycle= 4 hours at -20◦c in the freezer and 4 hours at + 20◦c in the curing tank water).
10.1. Compressive Strength
Table [22]. Test results of the compressive strength for air entrained concrete samples, where was measured after periods of maturation in tank water as a control samples (witness) and compressive strength of samples after 200 cycles freezing and thawing
Tablica [22]
|
Compr. strength after 200 cykles Freezing & Thawing |
Average. |
Control Compr. strength |
Average |
Loss in strength |
W/C |
GGBS |
|||||
|
|
1 |
2 |
3 |
strength |
1 |
2 |
3 |
strength |
% |
% |
% |
|
A – 1 |
39.4 |
41.2 |
38.5 |
39.7 |
43.1 |
39.9 |
41.2 |
41.4 |
4.1 |
|
0 |
|
A – 2 |
42.6 |
42.3 |
41.7 |
42.2 |
44.3 |
43.6 |
45.8 |
44.6 |
5.4 |
0.45 |
30 |
|
A – 3 |
43.1 |
40.8 |
41.3 |
41.7 |
45.9 |
45.0 |
43.8 |
44.9 |
7.1 |
|
50 |
|
A – 4 |
37.4 |
36.1 |
34.9 |
36.1 |
39.3 |
40.4 |
39.7 |
39.8 |
9.3 |
|
70 |
Graph (15) – Research results of compressive strength for aerated concrete samples after 200 cycles of freezing and thawing
The results have shown that, the increase in compressive strength for air aerated concrete samples containing GGBS (39.8÷ 44.6N), where was measured after periods of ripining in tank water as a control samples is significant.
We noteced a clearly decrease in compressive strength in all samples mixes after 200 cycles freezing and thawing.
Graph (16) – Research results of the decrease in compressive strength [%] for aerated concrete samples after 200 cycles of freezing and thawing.
The results showed after 200 cycles freezing and thawing that, less decrease in compressive strength in air entrained concrete samples with 100% CEMII/A-L the decrease was (4.1%) and more decrease in the samples containing GGBS (5.4 ÷ 9.3 %).
Graph (17) – Research results of the decrease in compressive strength [%] for aerated concrete samples after 200 cycles of freezing and thawing
The results showed after 200 cycles freezing and thawing that, less decrease in compressive strength in concrete samples with 100% CEMII/A-L the decrease was (1.7N) and more decrease in samples containing GGBS (2.4 ÷ 3.7 N).
10.2. compressive strength of control (witness) samples
Summary – Compression Strength – Control (witness) Samples
Table [23]. Test results of the air entrained control sample compressive strength, where was measured after periods of maturation in tank water
Tablica [23].
|
W/C = 0.45 |
CEM II |
CEM II/GGBS |
CEM II/GGBS |
CEM II/GGBS |
|
Cement content % |
100 |
70/30 |
50/50 |
30/70 |
|
Compressive strength of control (witness) samples [N/mm2]] |
41.4 |
44.6 |
44.9 |
39.8 |
Graph(18) – Research test results of the control (witness) compression strength for air entrained concrete samples
The results showed that, the increase in air entrained concrete compressive strength of control mixes (witnesses) containing 30% and 50% GGBS was significantly higher than other concrete made with 100% CEM II/A-L where was (41.4N).
The highest compressive strength in the control mixes was the samples containing 50% GGBS (44.9N).
10.3. Summary – Durability Test – under the influence of compressive Strength
Table [24]
|
W/C = 0.45 |
CEM II |
CEM II/GGBS | CEM II/GGBS | CEM II/GGBS | |||||
|
Cement Content % |
100 |
70/30 |
50/50 |
30/70 |
|||||
|
Compressive strength after 120 day maturated in water [N/mm2]] |
41.4 |
44.3 |
43.8 |
39.1 |
|||||
|
Compressive strength of Control Samples [N/mm2]] |
41.4 |
44.6 |
44.9 |
39.8 |
|||||
|
Compressive strength after 200 cycles Freezing & Thawing [N/mm2] |
39.7 |
42.2 |
41.7 |
36.1 |
|||||
|
Loss in Compressive strength in [%] |
4.1 |
5.4 |
7.1 |
9.3 |
|||||
|
Loss in Compression strength in [N] |
1.7 |
2.4 |
3.2 |
3.7 |
|||||
10.4. Durability Test – Mass Loss of concrete samples:
Table [25]. Test results of loss of mass for air entrained concrete samples before and after the test, after 200 cycles of freezing and thawing
Table [25]
|
Mass of samples after 200 cykles Freezing & Thawing |
Averag of |
Mass of samples before test |
Average of |
Loss In mass |
W/C |
GGBS |
|||||
|
|
1 |
2 |
3 |
mass |
1 |
2 |
3 |
masa |
% |
% |
% |
|
A – 1 |
2428 |
2421 |
2424 |
2424 |
2430 |
2425 |
2426 |
2427 |
0.12 |
|
0 |
|
A – 2 |
2420 |
2426 |
2418 |
2421 |
2426 |
2429 |
2424 |
2426 |
0.21 |
0.45 |
30 |
|
A -3 |
2417 |
2410 |
2414 |
2414 |
2428 |
2419 |
2423 |
2423 |
0.37 |
|
50 |
|
A – 4 |
2405 |
2416 |
2400 |
2407 |
2421 |
2425 |
2416 |
2421 |
0.58 |
|
70 |
Graph (19) – Research results of the loss in mass in [g] for aerated concrete samples after 200 cycles of freezing and thawing
The results have shown for aerated concrete samples after 200 cycles freezing and thawing that, the loss in mass was only (3g) for 100% CEMII/A-L, and for samples containing GGBS the loss of mass was between (5÷14g).
Graph (20) – Research results of the loss in mass in [%] for aerated concrete samples after 200 cycles of freezing and thawing
The results have shown for aerated concrete samples after 200 cycles freezing and thawing that, the loss in mass was only (0.12%) for samples 100% CEMII/A-L, and for samples containing GGBS was the loss of mass between (0.21÷0.58%).
10.5. Summary – Durability Test – under the influence of mass loss:
Table [26]
|
Air entrained Concrete |
|||||||||||||||||||||||||
|
Loss of mass |
|||||||||||||||||||||||||
|
W/C = 0.45 |
|||||||||||||||||||||||||
|
Professor Pawel Lukowski. Head of the Department of Building Materials Engineering. Warsaw University of Technology
Dr. Eng. Joanna Julia Sokolowska. Department of Building Materials Engineering. Warsaw University of Technology
MSc. Eng. Ali Salih Technical and Quality Manager – Casey Concrete, Gorey Co. Wexford
Part I – DURABILITY OF CONCRETE CONTAINING GGBS IN EXPOSED TO FREEZING AND THAWING CONDITIONS
1- Abstract 2. Background 3. Prisms analysis of cement samples (MORTARS) 4. Test results of the Prisms 5. Test on Without Air Entrained concrete samples: 6. Strength test results 7. Durability Test
Part II – DURABILITY OF CONCRETE CONTAINING GGBS IN EXPOSED TO FREEZING AND THAWING CONDITIONS
8. Air Entrained Concrete 9. Strength test results of the air entrained concrete samples maturated in tank water 10. Durability Test 11. Conclusions of the study/a> 12. Literature