REPORT

Corrosion of Steel in Concrete

Person	Group	Semestr	Date
1. Borkowski Tomasz	A	I	20 X 08r.
2. Kowalska Ewa
3. Kuźma Dawid
4. Mucha Bartosz
4. Wochnik Michał

1. Examined metal: stainless steal, density:
, area:

2. Corrosion environment:

Solution A: 1M HCl

Solution B: Ca(OH)₂

3. Measure performance:

Item	No	Sample characteristics				Corrosion rate calculation
				Exposure time T [min]	Sample mass			Mass loss WL: [g/m2*day]	Corrosion rate CR [mm/year]
						Mass before test mb [g]	Mass after test ma [g]			Mass difference W [g]
1.	2	15	6,4010	6,3945	0,0065	0,0169	0,0482
2.	55	15	6,8035	6,7987	0,0048	0,0125	0,0356
3.	13	30	5,7322	5,7213	0,0109	0,0284	0,0808
4.	42	30	6,7285	6,7230	0,0055	0,0143	0,0408
5.	39	45	6,8009	6,7875	0,0134	0,0349	0,0993
6.	40	45	6,2118	6,2016	0,0102	0,0266	0,0756
7.	29	60	5,0767	5,0696	0,0071	0,0185	0,0526
8.	16	60	5,2438	5,2387	0,0051	0,0133	0,0378
9. z	48	60	6,8538	6,8537	0,0001	0,0003	0,0007
10. z	17	60	5,6625	5,6624	0,0001	0,0003	0,0007

4. Prepare chart:

To prepare those diagrams we need additional table with some average values of samples taken out in the same time. This table will be the base for our diagrams:

No	Item	Exposure time T [min]	Average mass difference [g]	Average mass loss [g/m2*day]	Average corrosion rate [mm/year]
1.	2,55	15	0,0057	0,0147	0,0419
2.	13,42	30	0,0082	0,0214	0,0608
3.	39,40	45	0,0118	0,0308	0,0875
4.	29,16	60	0,0061	0,0159	0,0452
5. z	48,17	60	0,0001	0,0003	0,0007

5. Conclusions

- Acid environment foster corrosion, significant difference in mass was discovered among samples placed in sulphuric acid solution.

- Alkaline environment protect metal against corrosion, no significant difference in mass was discovered among samples placed in lime water solution.

- Acid rains and contaminated environment can limit lifetime of rebars, and other metal structures

- Corrosion of metal outcome gradually, its tempo is unstable, firstly it's relatively slow, but when metal pore solution pH is nearly neutral, it's starting to increase.

4

Date of laboratory practise: 20.10.08

Lecturer: mgr inż. Anna Kowalik

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