Defining the thermal conductivity of thermally heterogeneous hollow wall bricks used as elements for increasing the comfort of buildings

The article presents numerical calculation analysis in the scope of determining thermal conductivity coefficient λeq [W/(m·K)] of thermally heterogeneous hollow bricks of thermally heterogeneous structure (a combination of structural material with thermal insulation material). Numerical calculations were conducted by means of professional software TRISCO-KOBRU 86, serving thermal circulation analysis in a 2D field in stationary approach. The analyzed hollow wall bricks may be used, for instance, as a structural layer of layered outer walls of a building. In the article also the results of the Uc thermal conductivity coefficient calculations for double-layer walls with the use of the analyzed hollow wall bricks are presented in regard to thermal requirements.

Passive evaporative cooling through water-filled bricks: a preliminary investigation

Direct evaporative cooling is widely known to be an energy efficient air-conditioning option for arid and semi-arid climates. However, care must be taken on humidity ranges achieved indoors. Existing literature presents several options for integrating evaporative cooling within buildings for passive cooling applications. This work aims at expanding the current knowledge by focusing on the use of water-filled hollow bricks to implement evaporative cooling of air in contact with the brick’s surfaces. A prototype is built and experimentally characterized under controlled air velocity, air temperature and relative humidity conditions. Results on the psychrometric conditions achieved under different geometric arrangements (i.e., with one, two or three rows of four bricks each) are presented and discussed. Insights on likely building integration of the system for passive cooling purposes in farms and agriculture applications are eventually given.

Utilization of Phosphoric Acid and Lime for Stabilizing Laterite for Lateritic Bricks Production

This study investigates the use of phosphoric acid (H3PO4) and lime in stabilizing lateritic soil for lateritic bricks production. Varying percentages (0, 2, 4 and 6%) of 1 M H3PO4, 5% lime and their combinations were mixed with lateritic soil for stabilization purpose. Hollow bricks were produced from the different mixes. The bricks were cured for 7, 14 and 28 days under ambient air condition. The compressive strength (fc), bulk density (pb), dry density (pd) and water absorption rate were determined at each of the curing days while the modulus of rupture (fr) and pH were determined after 28 days. The results show a maximum fc of 0.93 N/mm2 and 0.87 N/mm2 were obtained at 5% and 4% H3PO4 stabilization. The maximum pb and pd of 15.2 kN/m3 and 14.9 kN/m3 respectively were obtained at 4% H3PO4 stabilization. The maximum fr of 0.2 N/mm2 was obtained at combined 4% H3PO4 and 5% lime stabilization while none of the bricks passed the water absorption test.

ANALISIS KESELAMATAN DAN KESEHATAN KERJA (K3) MENGGUNAKAN METODE HAZARD AND OPERABILITY (STUDI KASUS. PT IGASAR)

Produksi dan penjualan bahan bangunan lain yang berbasis semen, seperti hollow bricks (Beton Cetak) dan paving blok. Tujuan penelitian ini adalah menganalisis bahaya dengan metode HAZOP, menentukan nilai safety integrity level (SIL) dan menentukan solusi yang dapat diterapkan dilantai produksi hollow brick di PT. Igasar. Hasil penelitian menunjukkan bahwa terdapat 6 jenis kecelakaan kerja dengan 4 sumber bahaya. Berdasarkan data penelitian dari tahun 2015 hingga 2019, kecelakaan paling banyak terjadi pada tahun 2019 yaitu sebanyak 13 karyawan. Hal tersebut disebabkan oleh sikap pekerja yang kurang memperhatikan keselamatan diri. Kemudian ditemui 4 sumber bahaya yang menyebabkan kecelakaaan kerja, pada karyawan yaitu sikap pekerja, peralatan kerja, benda asing dan lantai basah. Berdasarkan sumber bahaya yang didapatkan perangkingan risiko yaitu sikap pekerja memiliki risk level ekstrim, peralatan kerja memiliki risk level risiko rendah, benda asing pada area kerja memiliki risk level risiko sedang dan pada lantai basah memiliki risk level risiko tinggi. Maka didapatkan bahwa sikap pekerja menjadi prioritas yang harus diperbaiki oleh pihak perusahaan.

CHEMICAL CORROSION PROCESSES OCCURRING IN THE MATERIAL OF LARGE-BLOCK POROUS CERAMICS

Large-block porous ceramics, which enter the market of building materials, have a number of undeniable qualities: low thermal conductivity, low density, high aesthetic qualities. According to its design features, this material is a modern prototype of hollow bricks used in construction since the nineteenth century. Field studies of the work of enclosing structures using hollow bricks have shown that in many cases, the bricks laid in the enclosing structures of buildings 60-80 years ago were significantly destroyed. In this case, the destruction mechanism does not depend on the polythermal load on the material. The hypothesis that the destruction is associated with the chemical destruction of the material was investigated using the developed method for determining the chemical resistance of the material of wall ceramics. The conducted studies confirmed the hypothesis. Studies of the chemical resistance of the material of large-block porous ceramics should be taken into account in the production technology of ceramics.