2.12
Yığma Duvarlarda Harç Derzlerinin Bozulması
Harç derzinin bozulması, derzlerde su birikmesinin donma-çözülme döngülerinden kaynaklanan hasara yol açmasıyla, duvar örgüsü yapılarında önemli bir e…
Bir duvar duvarı, yağmur suyuna maruz kaldığında, genellikle duvarın harç dolgulu derzlerinde su toplar.
Derzlerde toplanan su, donma üzerine tekrar tekrar genleşmeye ve çözülme üzerine erimeye maruz kaldığında, duvar birimlerini bağlayan harçta çatlaklar oluşturur.
Sonunda, derzlerdeki harç ayrılır ve pul pul dökülür, bu da duvar birimlerini gevşetir ve suyun derzlerden duvara nüfuz etmesi için yollar oluşturur.
Bu, duvar derzlerinin suya dayanıklı harç ile iyice doldurulması ve duvar döşenirken sıkıca sıkıştırılmasıyla önlenir.
Şiddetli iklim koşullarına maruz kalan yığma duvarlar, harç derzlerinde önemli ölçüde bozulma yaşayabilir.
Bu gibi durumlarda, bozulmuş harcın düzgün bir derinliğe kadar tırmıklanmasını ve kesilmesini içeren yeniden işaretleme yapılır.
Bunu, derzlerdeki kalıntıların uzaklaştırılması ve yeniden işaretlenecek alanın ıslatılması takip eder.
Son olarak, derz taze harç ile doldurulur ve daha sonra bir derz aleti kullanılarak bitirilir ve su girişine karşı dirençli hale getirilir.
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Q1: What causes mortar joints in masonry walls to crack and deteriorate?
Water collected in mortar joints undergoes repeated expansion and contraction during freeze-thaw cycles. When water freezes, it expands, creating internal pressure that develops cracks in the mortar. Upon thawing, the water melts and the mortar contracts. This cycle eventually causes the mortar to split and flake off, loosening masonry units and creating pathways for water penetration.
Q2: How does water accumulation in masonry joints lead to structural damage?
Water accumulation in mortar joints causes spalling, where deteriorated mortar flakes off and loosens the masonry units. This weakens the structural integrity of the wall and creates openings for moisture intrusion. The repeated freeze-thaw cycles accelerate this deterioration, making the wall vulnerable to water penetration and further damage over time.
Q3: What preventive measures can protect mortar joints from deterioration?
Using weather-resistant mortar and ensuring thorough filling and compaction of joints during bricklaying prevents water accumulation and reduces deterioration. Proper compaction eliminates air voids where water can collect. In severe climates, even with these preventive measures, masonry in cold and hot weather conditions may still experience considerable joint deterioration over time.
Q4: What is the repointing process for deteriorated mortar joints?
Repointing involves raking and cutting out deteriorated mortar to a uniform depth, then removing debris from the joints. The area is wetted before filling with fresh mortar. Finally, a joint tool finishes the surface, making it resistant to water penetration. This process restores the structural integrity and weatherproofing of the masonry wall.
Q5: How does surface grouting differ from repointing in masonry repair?
Surface grouting is applied to hairline cracks in mortar joints to preserve the wall's structural integrity and appearance without extensive removal of mortar. Unlike repointing, which involves cutting out and replacing deteriorated mortar, surface grouting is a less invasive treatment for minor cracks that addresses moisture intrusion while maintaining the existing joint structure.
Q6: Why is proper mortar compaction critical during masonry construction?
Thorough compaction of water-resistant mortar during bricklaying eliminates air voids and ensures tight joints. This prevents water accumulation in the joints and reduces the risk of freeze-thaw damage. Well-compacted mortar creates a denser barrier that resists water penetration and significantly extends the service life of the masonry wall.
Q7: What role does cavity drainage and flashings play in preventing mortar joint damage?
Cavity drainage and flashings in masonry walls direct water away from the mortar joints, reducing water accumulation that triggers freeze-thaw deterioration. By managing moisture flow through the wall assembly, these systems protect mortar joints from repeated wetting and drying cycles, preserving joint integrity and preventing spalling and loosening of masonry units.