This research studied about mixing material to make the cement block with corncob to get a lighter weight but still have industry standard strength for non-bearing concrete block (TIS. 58-2530). Normally general cement block use 1:2 ratio by weight of cement and flour rock respectively The corncob were ground through a standard 3/8 inches sieve and were used to replace the flour rock using a ratio of 0% 3% 5% 7% and 9% by weight and setting the ratio of water per cement as 36% 40% 44% and 48% by weight. The compressive strength of 7x19x39 centimeters cement block mixed with corncob was tested at the age of 28 days. The test results to make cement block mixed with corncob showed the suitable ratio 3% corncob using instead of flour rock. The average compressive strength of the blocks was 20.09 kg/cm2 and the percent of water absorption was 12.23 % which past the Thai Industry Standard (TIS 58-2530)

The objective of this study aims to develop a concrete boat by using lightweight concrete. The use of granular foam replaced the aggregate in various quantities to reduce the weight of boat. The replacement ratios of aggregate by the granular foam were 0 25 50 75 and 100% by volume of aggregate. The test results of compressive strength tensile strength modulus of rupture and unit weight of concrete were used to find out the appropriate mixture for producing the concrete boat. The results indicated that the appropriate mixture for producing concrete boat was the replacement of aggregate by granular foam at 100% which had the compressive strength at 28 days of 50.59 kg/cm2 and the unit weight was 949.71 kg/m3. The weight of lightweight concrete was lighter than the normal concrete about 57%. The prototype of lightweight concrete boat which had 1.04 m wide 2.20 m long and 0.38 m height had about 50 kg of weight. The maximum weight capacity of the boat was 240 kg. The cost of a lightweight concrete boat was about 650 baht

The feasibility of wastewater treatment sludge from the power plant was studied as cement substituted material. The sludge were used as the air dried sample and the oven dried sludge at 300o C. Their properties then the optimum ratio of cement substituted portion for cement block were determined. In the control set; cement sand and water ratio were 1 2.75 and 0.825 (w/w) respectively while the treatment set sludge replacing were varied at 10 20 and 30 %. The blocks were produced and cured in tap water for 7 14 and 28 days and tested their compressive strength. The leaching ability of heavy metals namely Cd Cr Cu and Pb were determined by Waste Extraction Test or WET (according to the standard from the Notification of Ministry of Industry A.D. 2005) and Toxicity Characteristic Leaching Procedure; TCLP (US EPA method 1311). The results showed that the solution from cement block curing both of control set treatment block had basicidic pH range 11 – 12 and caused reduction of the heavy metal solubility. The solution conductivity range 5 - 7 mS/cm. The 10% dried sludge cement blocks were the suitable ratio compared with the control set which the maximum compressive strength at 28th day was 253.81 Kg/cm2 and 4.73 % moisture. All metal leaching abilities were less than those Notification and US EPA standard. Those optimum ratios 10 % can be applied to produce cement pot.

Recovering of tungsten carbide (WC) with the electrolysis solution in the electrolyte to a reaction with cemented carbide scraps 0.2-1.0 V between temperature from 30-80 C concentration 1-7 N hydrochloric acid solution within 48 hours the results showed the cemented carbide dissolution proper to the influence of voltage temperature and solution concentration. Can recovering tungsten carbide purity over 95.62% of which contain other ingredients include titanium 1.74% tantalum 1.68% and niobium 0.42% concluded that the electrolysis recovering tungsten carbide is appropriate under voltage is 0.4 V temperature 80C 7 N solution of hydrochloric acid recovery rate of tungsten carbide powder about 91.37% with an average particle size of 1.0 m

จากการทดลองวิจัยพบว่าจากผลการทดสอบ ตัวอย่างทดสอบมีกาลังอัดมีค่า 75 ksc. มากกว่า 70 ksc. เป็นไปตามคุณภาพคุณสมบัติของบล็อกประสาน วท. ดินซิเมนต์ที่มีคุณภาพได้มาตรฐาน ขนาดของเครื่อง เป็นแบบไฮดรอลิก อัดบล็อก 1 ก้อน รูปแบบการทางานแบบต่อเนื่อง ใช้ไฟฟ้า 220 V ขนาดเครื่องยนต์มอเตอร์ 5 แรงม้า ขนาดเครื่อง กว้าง 55 ซม. ยาว 55 ซม. สูง 110 ซม. น้าหนักเครื่อง 800 kg. ใช้วัสดุเหล็ก พ่นสี ผลการทดสอบความเร็วในการอัดขึ้นรูป จากผลการทดสอบความเร็วในการอัดขึ้นรูป ได้ 89 ก้อนต่อชั่วโมง หรือ 712 ก้อน ต่อวัน (8 ชั้วโมง) สูงกว่าการผลิตโดยแรงงานคนที่ 100-500 ก้อนต่อวัน และสูงกว่าเครื่องอัดไอดรอลิกทั่วไปขนาด 1 โมลที่ 500-700 ก้อน ต่อวัน จากผลการทดสอบวิจัยพบว่าการพัฒนาเครื่องอัดดินซิเมนต์สามารถนาไปผลิตในเชิงอุตสาหกรรมชุมชนได้เป็นอย่างดี