• 한국산학기술학회논문지
• /
• 제11권10호
• /
• pp.4031-4040
• /
• 2010

건축의 시작은 벽체를 구축하는 작업이다. 고대 로마건축에서의 석축기법은 매우 다양하며 새로운 기술의 반복적인 실험을 통하여 로마제국시대의 위대한 건축물들을 완성할 수 있었다. 본 논문에서는 고대로마의 석축기법을 양식적, 구조적, 재료적 또한 의장적인 다양한 관점에서 연구하여 그 변화의 과정을 단계적으로 분석하였으며 심도있는 자료의 수집과 정리를 통하여 로마건축이 인류에게 남긴 위대한 유산의 일부분을 깊이 있게 파헤쳐 보았다. 아직도 우리에게 영향력을 미치고 있는 로마건축의 연속성을 뒷받침 하는 것은 건축의 시작인 석축기술에 있다는 것도 재확인 할 수 있었다. 다양한 실험적 정신이 훌륭한 건축물이 만들어지는 토대가 됨을 로마건축은 보여주고 있다.

• 한국실내디자인학회논문집
• /
• 제27권3호
• /
• pp.90-99
• /
• 2018

The purpose of this study is to study how F.L. Wright reflected the climatic properties and materials of the region into creative ways of designing his architecture. The research method examined the design methods and use of materials by Wright in existing research literature and compares the space plans of housing works in Arizona. The research results will be summarized as follows : 1) For two-story houses, pilotis was used to avoid the hot air and the walls on the ground floor were often planned as thick wall. 2) In the fifties, F.L. Wright's design method changed in a circle from the vertical and horizontal lines. 3) F.L.Wright's Architectural form concepts and design concepts were extracted from local symbolic forms and natural forms. 4) F.L.Wright avoided Arizona's direct light but Indirect sunlight enters into the interior space. 5)External space was expressed as a closed space, while internal space was expressed as an open space. It's like an organic space. 6) Most of the housing materials used are stone and cement from rough deserts, and wood with low heat conductivity and thick concrete blocks to prevent the sunlight from rising above.

• 한국농촌건축학회논문집
• /
• 제20권4호
• /
• pp.19-29
• /
• 2018

This study examines the 1960s' townscape through the small-scale restoration model in Seongan-dong and Jungang-dong, Cheongju, one of the historical cities in South Korea. In the 1960s, Jungang-dong actively was developed outside the north gate of Cheongju castle, and Cheongju's townscape was changed by the relocation of railway station and construction of city hall. In the streetscape, the new roads, the east-west Sajik-ro and north-south Sangdang-ro were opened instead of old railroads, and they clarified the typical grid road system with the existing Seongan-ro, which connected north and south gate of the old castle. In the buildingscape, city hall was built in front of the railway station outside the north gate of old castle, and had a great effect on the existing buildings and facilities. The public, educational, and commercial buildings had been replaced by reinforced concrete, and the cement brick & block public housing were distributed widely. But the existing dwelling areas, located in the inside of old castle and outside south gate, showed the low and dense townscape, sustaining the former streets and building types.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2005년도 지반공학 공동 학술발표회
• /
• pp.293-301
• /
• 2005

The CSG(Cemented Sand and Gravel) method is construction technique using as raw materials earth and gravel generated from a local construction site, mixing them with cement and rolling with vibration rollers. Recently, The use of this method for cofferdam and large dam is gradually increasing in Japan. The purpose of an CSG mix design is to develop project specific properties to meet the structure design requirements. But uniform mix design of CSG method has not yet been established. The experience of practitioners from the geotechnical and concrete disciplines has given rise to two genernal approaches to mix design for CSG. This paper reports the concept of how to set the mix design according to modified Proctor compaction test process and the test results on properties such as compaction, compressive strength and modulus of elasticity that obtained by unconfined compression test.

• Computers and Concrete
• /
• 제9권2호
• /
• pp.119-131
• /
• 2012

Optimum packing of aggregate is an important aspect of mixture design, since porosity may be reduced and strength improved. It may also cause a reduction in paste content and is thus of economic relevance too. Several mathematic packing models have been developed in the literature for optimization of mixture design. However in this study, numerical simulation will be used as the main tool for this purpose. A basic, simple theoretical model is used for approximate assessment of mixture optimization. Calculation and simulation will start from a bimodal mixture that is based on the mono-sized packing experiences. Tri-modal and multi-sized particle packing will then be discussed to find the optimum mixture. This study will demonstrate that computer simulation is a good alternative for mixture design and optimization when appropriate particle shapes are selected. Although primarily focusing on aggregate, optimization of blends of Portland cement and mineral admixtures could basically be approached in a similar way.

• Advances in concrete construction
• /
• 제10권4호
• /
• pp.311-317
• /
• 2020

Performance of Sustainable materials continues through using of recycled waste construction materials to minimize the utilization of the natural resources. The cement industry is a major source of CO₂ in the atmosphere which is the main cause of global warming. Replacement of OPC with other sustainable cementitious materials has been the most interesting area of researches. This investigation focuses on the properties of alkali-activated mortar with the different replacement ratios of ceramic tile powder (CTP) by fine soil powder (FSP) (0 to 100)% and different molarities of sodium hydroxide concentrations. The experimental program was conducted by examining the compressive strength, water absorption, and water sorptivity. The results showed that the compressive strength of the specimens at age of (28, 56, and 90 days) increases with an increase in the amount of fine soil powder content and decreases at the age of 120 days. Also, minimum water absorption at the age of 90 days was found in the mixes containing 100% fine soil powder. However, fine soil powder replacement had a negative effect on the sorptivity and water absorption values at the age of 120 days. On the other hand, the 12M sodium hydroxide concentration was considered the optimum concentration compared to other concentrations.

• 한국농공학회논문집
• /
• 제52권4호
• /
• pp.73-81
• /
• 2010

The cemented sand and gravel (CSG) method is a construction technique that adds cement and water to rock-like materials, such as rivered gravel or excavation muck which can be obtained easily at areas adjacent to dam sites. This study was performed to evaluate the compaction and compressive strength properties of stress-strain, elastic modulus and fracture mode CSG materials reinforced polypropylene fiber. Polypropylene fiber widely used for concrete reinforcement is randomly distributed into cemented sand. The two types of polypropylene fiber (monofillament and fibrillated fiber) were used and fiber fraction ratio was 0, 0.2 %, 0.4 %, 0.6 % and 0.8 % by the weight of total dry soil. The effect of fiber fraction ratio and fiber shape on compaction and compressive strength were investigated. The optimum moisture contents (OMC) of CSG material increased as fiber fraction increased and the dry density of CSG material decreased as fiber fraction. Also, the maximum increase in compressive strength was obtained at 0.4 % content of monofillament and fibrillated fiber. CSG material behaviour was controlled not only by fiber fraction but also fiber distribution, fiber shape and fiber type.

• Computers and Concrete
• /
• 제20권3호
• /
• pp.283-290
• /
• 2017

The aim of this study is to investigate the effect of the bond strength of self-compacting mortars (SCMS) produced from ground pumice powder (GPP) as a mineral additive. In this scope, six series of mortars including control mix were prepared that consist of 7%, 12%, 17%, 22% and 27% of ground pumice powder by weight of cement. A total of 54 specimens of $40{\times}40{\times}160mm$ were produced and cured at the age of 3, 28 and 90-day for compressive and tensile strength tests and 18 specimens of $150{\times}150{\times}150mm$ mortar were prepared and cured at 28 days for bond strength tests. Flexural tensile strength and compressive strength of $40{\times}40{\times}160mm$ specimens were measured at the curing age of 7, 28 and 90-day. Mini V-funnel flow time and mini slump flow diameter tests were also conducted to obtain rheological properties. As a result of the study, it was observed that the SCMs containing 12% of GPP has the highest bond strength as compared to control and GPP mortars. Compressive strength slightly increased up to 12% of GPP.

• 대한토목학회논문집
• /
• 제9권4호
• /
• pp.83-92
• /
• 1989

강성포장(剛性鋪裝)에 대하여 더 좋은 공용성능(供用性能) 기대를 위한 개발과 파손발생에 대한 파손과정에 관하여 포장상태를 조사하게 된다. 본 논문(論文)은 공용중(供用中)인 시멘트콘크리트 포장(鋪裝)의 피로거동(疲勞擧動)과 탄성특성(彈性特性)에 대한 연구결과이다. 공용중(供用中)인 각(各) 포장(鋪裝)의 평균인장강도(平均引張強度)를 측정하기 위하여 Indirect tensile시험을 실시한 것이다. 변형측정(變形測定)은 이러한 특성의 변화 및 콘크리트의 탄성특성(彈性特性)을 구하기 위한 피로(疲勞)시험을 통하여 이루어진 것이다.

• Computers and Concrete
• /
• 제18권6호
• /
• pp.1065-1082
• /
• 2016

The main aim of this study is to predict the compressive and flexural strengths of self-compacting mortar (SCM) containing $nano-SiO_2$, $nano-Fe_2O_3$ and nano-CuO using wavelet-based weighted least squares-support vector machines (WLS-SVM) approach which is called WWLS-SVM. The WWLS-SVM regression model is a relatively new metamodel has been successfully introduced as an excellent machine learning algorithm to engineering problems and has yielded encouraging results. In order to achieve the aim of this study, first, the WLS-SVM and WWLS-SVM models are developed based on a database. In the database, nine variables which consist of cement, sand, NS, NF, NC, superplasticizer dosage, slump flow diameter and V-funnel flow time are considered as the input parameters of the models. The compressive and flexural strengths of SCM are also chosen as the output parameters of the models. Finally, a statistical analysis is performed to demonstrate the generality performance of the models for predicting the compressive and flexural strengths. The numerical results show that both of these metamodels have good performance in the desirable accuracy and applicability. Furthermore, by adopting these predicting metamodels, the considerable cost and time-consuming laboratory tests can be eliminated.