Development of Lightweight Concrete Interlocking Block Panel with Water Treatment Sludge and Expanded Metal Ferrocement

An innovative lightweight concrete interlocking block panel was developed to improve the lateral resistance of the infilled frame with green construction material.  The water treatment sludge obtained from Bang Khen water treatment plants was employed to replace the fine aggregate.   The lightweight concrete interlocking block panel was strengthened with ferrocement technique and expanded metal sheet.  Three sets of the strengthened block panels with various sizes of expanded mental were investigated: concrete block panel, interlocking block panel with thin bed adhesive mortar, interlocking block panel with thick bed cement mortar.   The concrete with mixed proportion of cement, sand, water, foaming agent, and sludge of 1:0.70:0.60:0.006:0.30 by weight was suitable for producing the lightweight concrete block according to the Thai Industrial Standard.  The compressive strength test of masonry prisms and the diagonal tension (shear) test were conducted for the three sets of the strengthened block panels.  The test results reveal that the interlocking block was superior to the conventional concrete block in terms of strength and ductility capacity due to the effect of interlocking between the block.  The shear key with thick bed cement mortar is more effective than the thin bed adhesive mortar typically used in the construction of lightweight concrete

Seismic Analysis of RC Frames with Brick Infill Panel Strengthened by Steel Cage and Expanded Metal

The seismic analysis of reinforced concrete infilled frame strengthened by using steel cage and expanded metal was investigated.  The strengthening technique of steel cage consisted of steel angle, batten and expanded metal sheet was employed. The brick infill panel was strengthened with ferrocement and expanded metal. The flexible base foundation was considered by modelling the pile foundation with the lateral and the vertical spring stiffness. Eight types of frames: four existing frames and four retrofit frames were analyzed by nonlinear static analysis and nonlinear time history analysis with 20 ground motion records.  It was found that the initial stiffness and the strength of the retrofit frames were significantly higher than those of the existing frames.  The observed seismic damage of the retrofit frames was decreased to the specified limit.  The initial stiffness of the frames with flexible foundation was lower than that of the fixed base resulting to the larger displacement and the higher seismic damage of the structures.        

Seismic Shear Strengthening of Reinforced Concrete Short Columns Using Ferrocement with Expanded Metal

Typical reinforced concrete short column is brittle in shear rather than flexure under lateral cyclic loading due to its shear deficiency.  This paper presents the improvement of seismic behaviour of the reinforced concrete short columns which were strengthened by using ferrocement with expanded metal.  Full scale experiments were conducted for two strengthened concrete columns with different volume fractions of expanded metal and the control specimen under lateral cyclic loading.  It was found that the seismic behaviour in terms of the shear strength, stiffness, displacement ductility, and energy dissipation were significantly improved.  The expanded metal mesh with the high specific surface provided the better performance for controlling the crack propagation.  The brittle shear failure mode of the stirrup was reduced and the ductile flexure mode of the longitudinal reinforcement was dominant.  The reduced shear force of the stirrup was compensated by the shear force of the expanded metal reinforcement which experienced relatively large strain.  The technique of steel angle installation at the corners of column can successfully prevent the effect of sharpened corner wrapping of the mesh.  A model to predict the shear strength of the strengthened column is presented in term of the global efficiency factor for expanded mental.    &nbsp

Seismic Strengthening of RC Frame and Brick Infill Panel using Ferrocement and Expanded Metal

This paper presents the strengthening of reinforced concrete frame and brick infill panel by using ferrocement technique reinforced with expanded metal. Analytical models of the strengthened frame and infill panel were proposed. An experimental study on the strengthened frames was conducted to verify the proposed models. Two control specimens and two strengthened specimens were compared: the bare frame and the infilled frame. Special strengthening techniques were employed to protect against two major failures: the beam and columns of the frame were fully strengthened to prevent shear failure, and the infill panel was protected against corner compression failure. The frames were investigated under constant vertical load and lateral cyclic load. The seismic behavior of the retrofit frames was compared with the control specimens. The strengthened frames showed the significant increase of strength up to 64% and 87%, and the ductility capacity was also improved 77% and 66% for the bare frame and the infilled frame, respectively. The proposed model of strengthening for the frame and infill panel predicted the lateral resistance of the RC infilled frame with a reasonable accuracy when compared to the observed experimental results

Direct damage controlled seismic design of plane steel degrading frames

A new method for seismic design of plane steel moment resisting framed structures is developed. This method is able to control damage at all levels of performance in a direct manner. More specifically, the method: (a) can determine damage in any member or the whole of a designed structure under any given seismic load, (b) can dimension a structure for a given seismic load and desired level of damage and (c) can determine the maximum seismic load a designed structure can sustain in order to exhibit a desired level of damage. In order to accomplish these things, an appropriate seismic damage index is used that takes into account the interaction between axial force and bending moment at a section, strength and stiffness degradation as well as low cycle fatigue. Then, damage scales are constructed on the basis of extensive parametric studies involving a large number of frames exhibiting cyclic strength and stiffness degradation and a large number of seismic motions and using the above damage index for damage determination. Some numerical examples are presented to illustrate the proposed method and demonstrate its advantages against other methods of seismic design. © 2014, Springer Science+Business Media Dordrecht

การระบายและการแพร่กระจายของโลหะในฝุ่นจากอุตสาหกรรมเครื่องปั้นดินเผาEmission and Dispersion of Metals in Particulate Matter from Pottery Industry

บทคัดย่อ ประเด็นสิ่งแวดล้อมในอุตสาหกรรมเครื่องปั้นดินเผาในระดับท้องถิ่นที่สำคัญ คือ ขั้นตอนการเผาที่ขาดระบบควบคุมมลพิษ ซึ่งอาจส่งผลกระทบต่อสุขภาพและสิ่งแวดล้อม การศึกษานี้ได้วิเคราะห์ความเข้มข้นของฝุ่นและโลหะในฝุ่นที่ระบายออกจากขั้นตอนการเผาที่ใช้ไม้เป็นเชื้อเพลิงและการแพร่กระจายของสารมลพิษในบรรยากาศด้วยแบบจำลอง AERMOD โดยเลือกโรงงานเครื่องปั้นดินเผาแห่งหนึ่งในอำเภอเมือง จังหวัดราชบุรี เป็นกรณีศึกษา ตัวอย่างฝุ่นถูกเก็บที่ปล่องระบายของเตาเผาตลอดขั้นตอนการเผา จำนวน 2 รอบการผลิต และวิเคราะห์ปริมาณฝุ่นด้วยวิธีกราวิเมตริก จากนั้นวิเคราะห์ปริมาณโลหะในฝุ่นทั้งหมด 15 ชนิด ด้วยเครื่อง ICP-OES ผลพบว่า มีความเข้มข้นของฝุ่นเฉลี่ย เท่ากับ 131 มิลลิกรัมต่อลูกบาศก์เมตร และพบโลหะ 8 ชนิด ได้แก่ Fe Al Zn Mg Ni Cr Mn และ Cu ส่วนผลการคาดการณ์ด้วยแบบจำลอง พบว่า ฝุ่นมีการแพร่กระจายสอดคล้องกับผังลมของพื้นที่ โดยพบความเข้มข้นของฝุ่นสูงสุด 24 ชั่วโมง (เฉลี่ยสองรอบการผลิต) ไม่เกินค่ามาตรฐานฝุ่นละอองขนาดเล็ก (PM10) ในบรรยากาศ ส่วนโลหะที่เป็นอันตราย (Cr Mn และ Ni) ไม่เกินเกณฑ์ที่ส่งผลต่อสุขภาพAbstractOne of the critical environmental issue of a local pottery production industry is an air pollution emission from burning process without control systems. This may seriously cause health and environmental impacts. This study analyzed particulate matter (PM) concentration and its metal composition released from the wood-fueled burning process of the pottery production. Prediction of the pollutants dispersion was also performed using AERMOD model. A pottery factory in Muang district, Ratchaburi province was selected as a case study. PM sampling was performed at stack’s furnace throughout the burning process in two production cycles. PM were quantified by means of gravimetric method. A number of 15 metal elements in PM were then analyzed by using the ICP-OES instrument. The results found that averaged PM emission was 131 mg/m3. There were totally 8 metal species found as follow: Fe, Al, Zn, Mg, Ni, Cr, Mn and Cu. The model’s dispersion estimations showed PM alignments agreed with wind roses of the study area. The 24-hours-highest PM concentration (averaged both of the two production cycles) and the hazardous metals – Cr, Mn and Ni – were found below the national ambient PM10 standard and health related guidelines, respectively

Recycling of thermoset polyurethane foams

A new way for recycling polyurethane (PU) foams is shown by scrap pulverization and subsequent compression molding of resulting particles. The compression molding stage is also called “direct molding” to highlight the absence of any linking agent or virgin material. Large disks, 190 mm in diameter, were molded by recycling foam scraps from motorcycle seats. Aluminum alloy molds and a hot parallel press plate press were used: the molding temperature was fixed to 180°C, the molding pressure to 4.2 MPa, and the molding time to 15 min, whereas the weight of the particles to mold was changed so as to obtain disks with different thickness. The final density of molded product was close to 1 g/cm3, resulting in a compacting factor of 14 in comparison with the initial PU foam. Indentation tests and tensile tests showed that final products exhibit good mechanical performances