• Advances in concrete construction
• /
• 제5권2호
• /
• pp.101-115
• /
• 2017

Cement kiln dust (CKD) is one of the most important waste materials in the cement industry. The large amount of this material, has encouraged researchers to propose new ways to recycle and reuse it. In this paper, effects of adding cement kiln dust to the ordinary Portland cement, on the physical and mechanical properties of ordinary and lightweight concrete were investigated. Results showed that concrete containing CKD, presents lower workability and modulus of elasticity; however, improvements in strength was observed by adding particular amounts of CKD. Eventually, it was found that adding 10% of cement weight CKD is the appropriate percentage for utilizing in manufacturing ordinary and lightweight concrete.

• 한국농공학회논문집
• /
• 제52권2호
• /
• pp.19-25
• /
• 2010

This study was conducted to determine the resilient modulus (Mr) and the unconfined compressive strength (UCS) of two recycled roadway materials such as recycled pavement material (RPM) and road surface gravel (RSG) with or without cement kiln dust (CKD). The recycled materials were blended with two CKD contents (5, 10 %) and 28 day curing time. Mr and UCS tests were also conducted after 10cycles of freezing and thawing to asses the impact of freeze-thaw cycling. Mr was determined conducting by the laboratory test method described by NCHRP 1-28A. Stabilized RPM and RSG had a modulus and a strength higher than unstabilized RPM and RSG. Mr and UCS of RPM and RSG mixed with CKD increased with increasing CKD content. The results indicated that the addition of CKD could be improved the strength and the stiffness of RPM and RSG. Therefore, RPM, RSG and CKD could be used as an effective materials in the reconstruction of roads.

• 한국건축시공학회지
• /
• 제12권1호
• /
• pp.87-97
• /
• 2012

This paper presents a method of estimating the setting time of cement mortar incorporating recycled aggregate powder (RP) and cement kiln dust (CKD) at various curing temperatures by applying an equivalent age method. To estimate setting time, the equivalent age using apparent activation energy (Ea) was applied. Increasing RP and CKD leads to a shortened initial and final set. Ea at the initial set and final set obtained by Arrhenius function showed differences in response to mixture type. These were estimated to be from 10~19 KJ/mol in all mixtures, which is smaller than those of conventional mixture ranging from 30~50 KJ/mol. Based on the application of Ea to Freisleben Hansen and Pederson's equivalent age function, equivalent age is nearly constant, regardless of curing temperature and RP contents. This implies that the concept of maturity is applicable in estimating the setting time of concrete containing RP and CKD. A high correlation was observed between estimated setting time and measured setting time. A multiregression model was provided to determine setting time reflecting RP and CKD. Thus, the setting time estimation method studied herein can be applicable to concrete incorporating RP and CKD in the construction field.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
• /
• pp.93-95
• /
• 2011

This study is to investigate experimentally the engineering characteristics of cement mortar incorporating both recycled aggregate powder (RP) below 0.08 mm and cement kiln dust(CKD). RP is substituted for fine aggregate ranged from 5~15% and CKD is also substituted for RP from 10~30%. The use of RP resulted in a decrease in flow value at fresh mortar, while an increase in CKD did not affect the flow value significantly. The combination of RP and CKD provided slight increase in compressive strength at early and 28 days and in the high curing temperature at early age showed an increasing Strength value.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
• /
• pp.559-562
• /
• 2000

This study is about the compensation of early age strength on mortar and concrete admixed with blast-furnace slag powder. For study, we have used fine powder of gypsum and kiln dust from cement factory. According to the test results, we have obtained proper mixing ratio of slag powder, gypsum and kiln dust for the compensation of early age strength on mortar and concrete property.

• 한국토양비료학회지
• /
• 제8권2호
• /
• pp.89-96
• /
• 1975

본(本) 실험(實驗)은 양회공업(洋灰工業)의 부산물(副産物)로 다량 생산(生産)되고 있는 양회분진(洋灰粉塵) 이화학적(理化學的) 특성(特性)과 수도(水稻)에 대한 토양개량제(土壤改良劑)로서의 효과(効果)를 검토(檢討)키 위해 실시하였다. 채취사용(採取使用)된 양회분진(洋灰粉塵)은 Suspension Preheater에서 별도로 집진한 By Pass (B. P)와 Cottrell 전기진기(電氣塵機)에서 집녹(集鹿)한 Electric Precipitate (E. P)의 두 종류이었다. 강원도(江原道) 철원군(鐵原郡) 동송면(東松面) 장흥리(長興里), 현무암지대(玄武岩地帶)에서 발달된 중점질(重粘質)의 산성토양(酸性土壤)에서 포장시험(圃場試驗)을 실시하였으며, 반당(反當) 양회분진(洋灰紛塵) 시용량(施用量)은 Ep, Bp 각 100kg, 200kg, 300kg과 대조구(對照區)를 포함(包含)한 7개 처리(處理)이었으며, 이 지방(地方) 장려품종인 농백(農白)을 공시(供試)하였다. 그 결과(結果)는 다음과 같이 요약(要約)할 수 있었다. 1. 양회분진(洋灰粉塵)은 농업용(農業用) 산성토양개량제(酸性土壤改良劑)로서 그 성분조성(成分組成)이 적합(適合)하다. Bp에 있어서 알카리도(度) 55%, 가용성(可溶性) 석회(石灰)와 고토(苦土) 함량(含量)이 각 41.7%와 9.8% 이고 수용성(水溶性) 규산(珪酸)은 4.5% 가리(加里)는 1%였다. Ep에있어서는 알카리도 53.5%, 가용성(可溶性) 석회(石灰)와 고토(苦土) 함량(含量)이 각 41.7%와 8.3% 이고 수용성(水溶性) 규산(珪酸) 함량(含量)은 1% 였다. 2. 분말도(粉末度)가 대단히 높아 토양중(土壤中)에서의 분응속도(反應速度)가 빠르고 석회물질(石灰物質)로서의 상대적(相對的) 효과(効果)가 높다. Ep는 270mesh를 전량(全量) 통과(通過)하고 Bp는 150mesh 이상이 95% 통과하고 270mesh를 통과하는 것은 68%였다. 3. 수도(水稻)의 대한 증수효과(增收効果)가 있었다. 석회소요량(石灰所要量)에 따른 양회분진(洋灰粉塵) 시용(施用)으로 (100kg/10a) Bp, Ep 각기 21%와 15%의 증수효과(增收効果)를 보았다. 증수원인(增收原因)은 주당수수(株當穗數), 수당입수(穗當粒數)와 천입중(千粒重)의 증가에 의한 것이었다. 4. 적당량(適當量)의 양회분(洋灰粉塵) 시용(施用)은 수도(水稻)의 수확량(收穫量)과 양분흡수량(養分吸收量)을 높였으나 과량(過量)의 시용(施用)은 오히려 이롭지 못했다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
• /
• pp.267-270
• /
• 2003

This study is intended to investigate the engineering properties of concrete, in which cement and fine aggregate are replaced with cement kiln dust(CKD), such as the properties of fresh concrete and hardened concrete and hydration heat history, for effective using method of CKD, a by-product produced in the process of making cement. According to the results, as the replacing ratio of CKD increases, slump and air content of concrete decreases remarkably due to an increase of viscosity and filling of the pores. As the properties of setting, initial and final setting time are shortened with an increase of the replacing ratio of CKD, and as the replacement of CKD for fine aggregate increases, setting time is shortened more greatly. Compressive strength increases due to filling of the pores and reduction of air content in comparison with plain concrete. When the replacement ratio of CKD for cement is 10% and 15%, peak temperature of hydration heat lowers slightly, but it goes up in the case of replacement of CKD for fine aggregate. Also, when cement and fine aggregate is replaced with CKD by 2.5% and 7.5% respectively(1C3S) in the case of replacement of CKD for cement and fine aggregate, it is highest.

• Geomechanics and Engineering
• /
• 제15권4호
• /
• pp.1005-1016
• /
• 2018

This paper presents an investigation on the properties of two types of cement kiln dust (CKD)-stabilized dredged sediments, silt and clay with a comparison to hydrated lime stabilization. Unconfined compressive strength (UCS) and California bearing ratio (CBR) tests were conducted to examine the optimal stabilizer content and classify the type of highway material. A strength development model of treated dredged sediments was performed. The influences of various stabilizer types and sediment types on UCS were interpreted with the aid of microstructural observations, including X-ray diffraction and scanning electron microscopy analysis. The results of the tests revealed that 6% of lime by dry weight can be suggested as optimal content for the improvement of clay and silt as selected materials. For CKD-stabilized sediment as soil cement subbase material, the use of 8% CKD was suggested as optimal content for clay, whereas 6% CKD was recommended for silt; the overall CBR value agreed with the UCS test. The reaction products calcium silicate hydrate and ettringite are the controlling mechanisms for the mechanical performance of CKD-stabilized sediments, whereas calcium aluminate hydrate is the control for lime-stabilized sediments. These results will contribute to the use of CKD as a sustainable and novel stabilizer for lime in highway material applications.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
• /
• pp.861-864
• /
• 2006

This study investigates the properties of light weight foamed concrete with variances in incorporating ratio of cement kiln dust(CKD). Test showed that an increase of CKD incorporating ratio decreased the fluidity of fresh concrete and increased the unit weight. A sinking depth of specimens incorporating CKD decreased, compared with that of control. As for the compressive strength, it firstly increased and then slightly decreased when incorporated CKD. Tensile strength values were similar to the values of compressive strength, but the ratio of comp. to tens. strength increased. Appearances density of specimens were all raged in KS and the thermal conductivity was also satisfied in KS; less than 0.05-0.160W/($m{\cdot}k$).

• 한국세라믹학회지
• /
• 제53권1호
• /
• pp.13-17
• /
• 2016

It is highlighted that increasing the adsorbent surface area on volumetric basis is very important in providing an easy access for gas molecules. Fine particles around $3{\mu}m$ of soft-burned dolomite kiln dust (SB-DKD) were hydrated to wet slurry samples by ball mill process and then placed in a chamber to use spray dryer method. Spherical granules with particle size distribution of $50{\sim}60{\mu}m$ were prepared under the experimental condition with or without addition of a pore-forming agent. The relationship between bead size of the pore-forming agent and size of SB-DKD particles is the most significant factor in preparation of spherical granules with a high porosity. Whereas addition of smaller beads than SB-DKD resulted in almost no change in the surface porosity of spherical granules, addition of larger beads than SB-DKD contributed to obtaining of the particles with both 15 times larger average pore volume and 1 order of magnitude larger porosity. It is considered that spherical granules with improved $N_2$ gas adsorption ability may also be utilized for other atmospheric gas adsorption.