MATERIALS USED FOR CONCRETE POLE CONSTRUCTION
CEM I 52,5R High early strength class Portland cement is used for the production. Taken as bulk, the cement is stored and protected in the silos of our concrete station. Each batch comes with a certificate of analysis, which is accepted in the result of compliance with our criteria specifications determined according to TS EN 197-1.
2. Concrete Aggregate
In the construction of concrete aggregate produced from crushed quarries;
8-16 mm is used as one class.
All parties are tested by the determined methods performed in our laboratory and are accepted if valid. The features which should be according to the TS 706 EN 12620 standards are regularly verified in our laboratory by experiments carried out in the framework of a continuous periodic plan. In addition, the recipe of concrete to be used in the production is created and its continuity is ensured by these experiments as well.
Determination of Particle Size Distribution (TS EN 933-1) as a result of the determination of granulometric combination curves,
Determination of Unit Weight (TS 3529)
Determination of fine material ratio (EN 933-10)
Determination of Specific Gravity and Absorption (EN 1097-6)
Determination of Surface Moisture Ratio (TSR 3523)
In the creation of concrete pole armature, the ribbed iron coils are used vertically and flat irons are used in the rings that make the horizontal frame.
Every party that comes with a certificate of analysis is accepted according to the admission limits of our specifications determined in compliance with TS 708. Kept in stock and protected in our covered facilities.(minimum standarts: yield:50kg/mm2 drawing:70kg/mm2)
1- fresh concrete
The use of concrete recipe created according to the TS 802 and TS EN 206-1 standards is only permitted after obtaining resistance in the result of concrete mixture experiments conducted in our laboratory and the verification of the desired concrete class. At the frequency specified in the Quality Plan;
Fresh Concrete Consistency Test (Slump Cone Method) (EN 12350-2)
Fresh Concrete Unit Weight Determination (EN 12350-6)
experiments are carried out. Also 1 day, 7 days and 28 days after production 15x15x15 cm fresh concrete samples are taken for confirming the desired compression strength of the concrete class.
Under the real production conditions steam sessions are applied to the sample which will be broken at the end of 1 day. Given steam session does not exceed 70 degrees.
7 and 28 day samples are kept in 20 oC ( + 2 oC) temperature-controlled water pools that are suitable for EN 12390-2 standards until the day of breakage.
1. Hardened Concrete
Concrete samples to be broken are broken in our hydraulic concrete press which is periodically calibrated according to the TS EN 12390-3 standards. The desired concrete class is confirmed based on the determined resistance outcomes.
The concrete poles and railway sleepers (completed products); are watered in order for concrete be protected (2) in the extremely hot summer months until the day of their shipment.
Alkali-silica reaction (ASR)
ASR is a chemical reaction often caused by cement alkali oxide (Na2O, K2O) formed between the aggregates containing reactive silica forms which creates an expansion effect on the concrete. In this reaction formation, severe cracks are seen in the next few years following the construction of the concrete.
The reason of these cracks is the expansion of alkali-silicate hydrate gel in the result of the reaction. This gel swells by absorbing water from the cement paste and spreads into the micro-cracks. Here also, the water absorbing gel formation enlarges the cracks especially by damaging the bonds of aggregate cement interface and leads to the disintegration of the concrete.
In order to prevent the formation of ASR; the total alkali value of the cement must be kept under control and the alkali re-activity of used aggregate must match TS 2517 standards of harmless (I. Region).