建筑工程 英文原文及翻译
Effect of Water Content on the Properties of Lightweight Alkali-Activated Slag Concrete
Keun-Hyeok Yang，Ju-Hyun Mun，Jae-Il Simand Jin-Kyu Song
Keyword：concrete、water content
Introduction
With the gradual growth of a global effort to reduce greenhouse gas emissions, a large section of the concrete industry has growing interest in minimizing the use of ordinary portland cement (OPC). This is because it is estimated that the production of 1 t of OPC requires about 2.8 t of raw materials, such as limestone and coal, and releases about 0.7 t of carbon dioxide (CO2) to the earth’s atmosphere from the decarbonation of lime in the kiln (Gartner 2004). As a result, since the late 1980s, toward the reduction of the use of OPC, various investigations have been conducted in several fields to develop a cementless alkali-activated (AA) ground granulated blast furnace slag binder together with a fly
ash–based geopolymer binder. As pointed out by Shi et al. (2006), AA slag binders and concrete will gradually attract a great deal of interest because of their extensive advantages of lower carbon
emissions and energy cost, higher-strength development, and better durability than with OPC concrete. In particular, AA slag concrete can effectively be applied to precast concrete products.
It is generally estimated that the amount of CO2 emitted from the consumption of fossil fuels for commercial and residential heating accounts for approximately 12% of the total CO2 emissions into the earth’s atmosphere. In addition, the nonnegligible amounts of CO2 are emitted from buildings or factory cooling. As a result, the development of energy saving systems and new and renewable energy
sources has become one of the hottest issues in building structures. The use of lightweight concrete as a building material is highly effective for saving energy because of the enhanced thermal insulation capacity through the lower thermal conductivity of lightweight aggregates. In addition, the application of structural lightweight concrete has several advantages as the reduction of the dead load because a
lower density of concrete allows for smaller and lighter weight structural member that can lead to more available space and improves the seismic resistance capacity of the upper structures.
Furthermore, the smaller and lighter elements of precast concrete members are preferred to make the handling and transporting system less expensive.
Synergy effects are expected when AA slag binder and lightweight aggregates are combined to produce environmentally friendly concrete because of the various advantages of both materials. One of the most significant effects is the highly reduced CO2 emission from concrete building structures by the use of AA slag binder with a lower CO2 emission and an energy-saving effect owing to the use of
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lightweight aggregates. In addition, precast concrete can be produced with good quality and
economical efficiency from an early higher strength development capacity of AA slag paste and a lower density of aggregates. However, the available experimental data (Collins and Sanjayan 1999; Yang et al. 2009) needed to determine a reliable mixing design and the mechanical properties of lightweight AA slag concrete are very rare. Unlike normal-weight OPC concrete, the workability and development of compressive strength of lightweight AA slag concrete is very sensitive to the hydration rate of the binder, the physical properties of lightweight aggregates, and the mixing conditions, such as the water content, water-binder ratio, and the proportion of lightweight aggregates. Yang et al. (2009) showed that the initial slump and the slump loss of AA slag concrete are significantly affected by the
water-binder ratio and lightweight aggregate proportions caused by the high water absorption capacity of lightweight aggregates. Collins and Sanjayan (1999) also pointed out that the internal curing effect on the slump loss and the shrinkage of concrete is strongly dependent on the state of moisture in lightweight aggregates and water content. In addition, a quicker slump loss is generally observed in lean AA slag concrete mixes than in OPC concrete because of the fast chemical reaction between various alumino-silicate oxides with silicate and/or the formation of silica-rich calcium silicate hydrates gel (Shi et al. 2006). Therefore, the water content and lightweight aggregate proportions need to be significantly managed for realizing the targeted slump and retarding the slump loss of lightweight AA slag concrete.
In the present study, five all-lightweight and five sand-lightweight AA slag concrete mixes were tested to evaluate the effect of the water content on the workability, mechanical properties, and shrinkage strain of the concrete. The rate of compressive strength development and the shrinkage strain were measured and compared with the empirical models proposed by American Concrete
Institute (ACI) 209 (ACI 1994) for normal-weight portland cement concrete. To examine the practical applicability of the lightweight AA slag concrete, the splitting tensile strength and the moduli of elasticity and rupture recorded from the concrete specimens were compared with the values predicted through various sources for lightweight OPC concrete, whenever possible. These sources included design equations specified in ACI 318-08 or Eurocode 2 [British Standards Institution empirical equations proposed by Slate et al., and a database compiled by Sim and Yang. 111517175
Experimental Details
Materials
Ground granulated blast furnace slag (GGBS) was activated by sodium silicate (Na2O·SiO2) and calcium hydroxide [Ca(OH)2] powders and used as a cementitious binder. The GGBS used for the source material had a high CaO content and SiO2-to-Al2O3 ratio by mass of 2.29. The specific gravity and specific surface area measured for the GGBS were 2.2 and 4,200 cm2/g, respectively. The
sodium silicate powder used was a compound of 50.2% sodium oxide (Na2O) and 45% silicon oxide (SiO2), producing a molar ratio (SiO2/Na2O) of 0.9. The purity of the Ca(OH)2 powder used was 95.8%.
Wang et al. showed that a higher strength of AA GGBS concrete was obtained by using liquid sodium silicate with a molar ratio of 1 to 1.5. Yang et al. (2008, 2010) also recommended that the ratios by weight of Ca(OH)2 to the binder, including the GGBS and alkali activators, and of Na2O in sodium silicate to GGBS were above 7.5% and 3%, respectively, to facilitate the chemical reaction by ion exchange between the silicate anions of the GGBS and the cations of the alkaline activators. Therefore, the Ca(OH)2-to-binder ratio was selected to be 7.5% and sodium silicate was added so that the Na2O-to-GGBS ratio would be 3% to produce a cementless AA slag binder.
Artificially expanded clay granules with maximum sizes of 19 mm and 5 mm were used for
lightweight coarse and fine aggregates, respectively. Locally available natural sand with a maximum particle size of 5 mm was also used for normal-weight fine aggregates. From X-ray diffraction
measurements, the main composition of the lightweight aggregates was quartz and calcium aluminum silicate. Fig. 1 shows that the lightweight aggregates were spherical in the shape and had a closed surface with a slightly rough texture. The core of the particle had a uniformly fine and porous structure that led to high thermal and acoustic insulation but induced high water absorption and low strength. In particular, the rate of water absorption of lightweight aggregates was extremely fast for the lightweight aggregates during the first 3 h, and then the absorption rate slowed down, as shown in Fig. 2. The specific gravity of the lightweight aggregates used was approximately 2.5 times lower than that of natural sand. The particle distribution of lightweight aggregates showed a continuous grading that satisfied the standard distribution curves recommended in the Korea Industrial Standard (Korean Standards Information Center 2006) specification, as plotted in 81615
Fig 1.
Shape and scanning electron microscope (SEM) images of the lightweight coarse aggregate used
Fig 2.
Water absorption rates of the aggregates used
Fig 3.
Particle distribution curves of the aggregates used: (a) lightweight aggregates; (b) normal-weight
aggregates (natural sand)
Mix Proportions
Five all-lightweight and five sand-lightweight AA slag concrete mixes were prepared by varying the water content per unit volume of concrete, as given in Table 2. Higher water-binder ratios can result in segregation in the lightweight concrete (ACI 1998). In addition, the compressive strength of lightweight AA slag concrete targeted in the present study was above 24 MPa for application to structural concrete members. From various preliminary tests, the water-binder ratio by weight and fine aggregate-to-total aggregate ratio by volume were fixed at 30% and 40%, respectively, in all concrete mixes. The mixture proportions of all the concrete specimens were determined on the basis of the weight method proposed by ACI 211. 2
Mixing, Curing, and Testing
Lightweight aggregates and natural sand were dampened for 24 h and then air-dried for another 24 h to simulate the saturated surface dried-state that is commonly employed in ready-mixed concrete plants. The alkaline binder and aggregates were dry-mixed in a pan mixer for 1 min, then water was added and mixed for another 1 min. For all the concrete mixes, a polycarbonate-based water-reducing admixture with an air-entraining agent was added by 0.5% relative to the amount of binder used. After the initial slump was tested, each mix was poured into various steel molds to measure the compressive strengths and other mechanical properties. Immediately after casting, all specimens were cured at room temperature until testing at the specified ages.
Test Results and Discussions
Initial Slump and Slump Loss
The initial slump, Si, of the lightweight AA slag concrete increased with the increase of water
content, which is generally observed in the lightweight OPC concrete as well (Neville 1995). At the same water content, the all-lightweight AA slag concrete showed a higher value of initial slump than the
9
sand-lightweight AA slag concrete, as shown in Table 3. The relatively round and smooth surface texture of the lightweight aggregates led to the improved initial workability of concrete.
The slump, S, of the concrete tested sharply decreased over the elapsed time, indicating that a
more notable slump loss developed in all-lightweight AA slag concrete than in sand-lightweight AA slag concrete, as shown in Fig. 2, and the rapid reaction of sodium silicate resulted in the quick setting of concrete. However, the increase of water content alleviated the slump loss of the concrete specimens. This may be attributed to the increased water content resulted in a decrease in the volume of
lightweight aggregates mixed in the concrete and an increase of the free water between hydrated gels., the relative slump, S/Si, of lightweight AA slag concrete can be approximately expressed as kT+1 with respect to the elapsed time, whereas S is slump at a specified time after the concentration and kind of alkali activator have an effect on the slump loss of concrete, this is seldom evaluated quantitatively, as reliable test data are very rare. Therefore, based on a nonlinear multiple regression analysis
considering the effect of only the volumes of the water content, Wv, and the lightweight aggregates, Lav, the rate of the slump loss, k, of lightweight slag concrete activated by Ca(OH)2 and Na2O·SiO2 can be expressed in the following form, as presented in Fig. 5:
Fig 4.
Relative slump against the elapsed time: (a) all-lightweight concrete; (b) sand-lightweight concrete
Fig 5.
Effect of the volumes of water and lightweight aggregates on the rate of slump loss
The failure planes of lightweight concrete generally pass through the lightweight aggregates and the number of interfacial cracks between lightweight aggregates and pastes increases with the increase in the amount of lightweight aggregates . As a result, the reduced volume of lightweight
aggregates mixed in the concrete because of the increased water content can lead to a slightly higher compressive strength of concrete. Additionally, the compressive strength of lightweight concrete
increased with the increase of its dry density, showing a similar increasing rate in both lightweight AA
slag and OPC concretes, as presented in Fig. 6. At the same dry density, a higher strength was
observed in lightweight AA slag concrete than in lightweight OPC concrete. It is generally known that the sodium-containing hydrated gels formed in AA slag pastes have low and tighter intensities than those generally observed in OPC pastes. This more elaborated gel product reduces interfacial cracks between lightweight aggregates and pastes, which can lead to an increase of compressive strength of
concrete.
Fig 6.
Dry density versus 28-day compressive strength
In general, the development of the compressive strength of OPC concrete is simulated as a parabolic function, as the increasing rate of compressive strength development decreases with the increase of age. The ACI 209 (ACI 1994) proposed the compressive strength development of cement concrete with age in the following form:
where fc′(t) = compressive strength at age t (in days). The constants A1 and B1 in Eq. (2) generally relate to the development of strength at an early age and a long-term age, respectively. In particular, lower values of A1 and B1 indicate higher rates of compressive strength development at the early and
long-term ages, respectively. The compressive strength development of concrete tested occurred in a parabolic shape, as shown in Fig. 7. From the test results given in Table 3, the constants A1 and B1 in Eq. (2) were determined from nonlinear regression analysis using the SPSS software, whereby a
correlation coefficient above 0.96 was obtained for all the concrete specimens. 1
Fig 7.
Typical compressive strength development of all-lightweight AA slag concrete
The constants A1 and B1 determined from the concrete tested are plotted in Fig. 8. In the same figure, both constants specified in ACI 209 (ACI 1994) for cement concrete are also given for comparisons. The strength gain of lightweight AA slag concrete at an early age was highly rapid, indicating that the compressive strength at 1 day reached as high as above 75% of the 28-day compressive strength. As a result, the constant A1 for lightweight AA slag concrete was lower than that
1
for OPC concrete and even that for high early strength portland cement concrete cured under steam, as shown in Fig. 8
.
Fig 8.
Comparisons of both constants in Eq. (2) determined from concrete specimens and specified in ACI 209 (ACI 1994) 1
Splitting Tensile Strength
The normalized splitting tensile strength slightly increased with the increase of the water
content, revealing a higher fsp/ in sand-lightweight AA slag concrete than in all-lightweight AA slag concrete, as listed in Table 4. This indicates that the increase of ρc caused by the increased water content and the use of normal-weight fine aggregates can lead to an increase of fsp/
Fig. 9. At the same ρc, a higher fsp
/, as plotted in was observed in lightweight AA slag concrete than in lightweight OPC concrete. However, it is necessary to collect more experimental data for reliable comparisons of both types of concrete. Moreover, fsp of concrete tested is commonly higher than that predicted from the empirical equation recommended by Slate et al. (1986), but slightly lower than the predictions obtained from the Eurocode 2 (BSI 2004) equation, regardless of ρc
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Conclusions
To evaluate the structural safety and practical application of lightweight AA concrete, various
mechanical properties of the concrete need to be examined according to the different parameters and compared with code provisions for OPC concrete, as the workability and mechanical properties of concrete are significantly affected by the characteristics of binder and aggregates, as well as mixing proportions. In addition, empirical equations to predict the mechanical properties of lightweight AA concrete should be proposed on the basis of extensive test data to consider the various influencing factors. Therefore, it is necessary to collect experimental data on various properties of lightweight AA concrete according to the variations in mix conditions.the following conclusions can be drawn:
1. 1.
The slump of concrete tested sharply decreased over the elapsed time, showing that a
more notable slump loss developed in all-lightweight AA slag concrete than in
sand-lightweight AA slag concrete. However, the increase of the water content
alleviated the slump loss of lightweight AA slag concrete.
2. 2.
The compressive strength of lightweight AA slag concrete slightly increased with the
increase of water content, showing a higher strength in sand-lightweight AA slag
concrete than in all-lightweight AA slag concrete. In addition, the increasing rate of
compressive strength against the dry density in lightweight AA slag concrete is similar to
that observed in lightweight OPC concrete.
3. 3.
The rate of development of compressive strength of lightweight AA slag concrete cured
under room temperature was comparable to that of steam-cured early strength portland
cement concrete.
4. 4.
The splitting tensile strength and the moduli of rupture and elasticity of lightweight AA
slag concrete were comparatively better than those of lightweight OPC concrete; and as
a result, they can be conservatively evaluated using the empirical models of Slate et al.
(1986) or ACI 318-08 (ACI 2008) proposed for lightweight OPC concrete.
5. 5.
The unrestrained shrinkage strain of lightweight AA slag concrete linearly increased until
the age of 14 days, remained nearly constant until 28 days and thereafter, sharply
increased again. Overall, the shrinkage strain measured from the lightweight AA slag
concrete specimens was larger than that predicted from the empirical model specified in
ACI 209 (ACI 1994) at an early age and after 40 days, regardless of the water content. 1133
Reference：
1. American Concrete Institute (ACI). (2008). “Building code requirements for structural concrete
and commentary.” ACI 318R-08
, Farmington Hills, MI. | first citation in article
2. Kayali, O. (2008). “Fly ash lightweight aggregates in high performance concrete.” Constr. Build.
Mater., 22(12), 2393–2399
. | first citation in article
3. Pacheco-Torgal, F., Castro-Gomes, J., and Jalali, S. (2008). “Alkali-activated binders: A review.
Part 2: About materials and binder manufacture.” Constr. Build. Mater., 22(7), 1305–1322. | first citation in article
4. Sim, J. L., and Yang, K. H. (2010). “Mixing design of lightweight concrete.” J. Korea Concr. Inst.,
22(4), 559–566
. | first citation in article
5. Collins, F., and Sanjayan, J. G. (1999). “Strength and shrinkage properties of alkali-activated
slag concrete containing porous coarse aggregate.” Cem. Concr. Res., 29(4), 607–610
. | first citation in article
含水量对轻质碱矿渣混凝土性能的影响
Keun-Hyeok Yang，Ju-Hyun Mun，Jae-Il Simand
关键字：混凝土、水含量
介绍
随着全球更加努力的减少温室气体排（OPC）的使用产生浓厚的兴趣。因为据估计，1吨的普通硅酸盐水泥需要大约2.8吨的原放量，很大一部分混凝土行业对于减少普通硅酸盐水泥用料，如石灰石和煤及约0.7吨的二氧化碳（CO2）排放到地球大气层从窑石灰中（Gartner 的2004年的脱碳）。因此，20世纪80年代后期以来，对于减少普通硅酸盐水泥的使用，各种调查已在多个领域进行开发一种碱激活水泥（AA）的地面粒状高炉矿渣与粉煤灰基无机矿物聚合物粘结剂粘结剂一起。正如Shi et al.指出，AA渣粘结剂和混凝土将因为其广泛的优势，降低二氧化碳排放量和能源成本，而且高强度的发展，更好的与OPC混凝土的耐久性，逐渐引起更多的关注。尤其是AA矿渣混凝土可以有效地应用于预制混凝土制品。
据一般估计，从进入地球大气层约12％的二氧化碳排放总量为商业和住宅供
暖帐户化石燃料消费排放的二氧化碳量。此外，不可忽视的二氧化碳排放来自建筑物或工厂冷却。因此，节能系统和新能源和可再生能源的发展，已成为建筑结构的热点问题之一。轻质混凝土作为建筑材料的使用是非常有效的对于节约能源，因为通过较低的导热轻质骨材增强了保温能力。另外，结构性轻质混凝土的应用，为减少静荷载有一些优势，因为混凝土的密度较低，允许更小，重量更轻的结构构件，可导致更多的可用空间，并提高了上部结构的抗震能力。此外，预
制混凝土构件小，重量更轻的元素，优先处理和传输系统的成本较低。
预计当AA渣粘结剂和轻质骨材，因为这两种材料的各种优势相结合，产生的环保混凝土的协同效应。其中一个最显着的影响是高度减少的从AA渣粘结剂使用较低的二氧化碳排放量和节能效果，由于使用轻质骨材混凝土建筑物的二氧化碳排放量的。此外，预制混凝土，就可以生产出优良的品质和经济效益，从早期强度较高AA渣糊的开发能力和密度较低的聚集。然而，现有的实验数据（柯林斯和Sanjayan的19995。;杨等人200917）需要确定一个可靠的混合设计和轻量级AA矿渣混凝土的力学性能是非常罕见的。与正常体重的OPC混凝土，和易性和轻量级AA矿渣混凝土抗压强度发展是非常敏感的粘结剂的水化速度，轻骨料的物理性质，化学性质，混合条件，如水分含量，水胶比，轻集料的比例。杨等人。 （200917），水胶比和高水轻集料的吸收能力所造成的轻骨料比例显着影响，AA矿渣混凝土初始坍落度和坍落度损失。柯林斯和Sanjayan（19995）也指出，坍落度损失和混凝土的收缩内部的固化效果是强烈的依赖状态中的水分轻骨料
和水含量。此外，更快的坍落度损失一般在精益AA矿渣混凝土混合比在OPC混凝土由于硅酸盐和/或形成富硅硅酸钙水合物凝胶（施雅风等各种铝硅酸盐氧化物之间的快速化学反应等。200611）。因此，水分含量及轻骨料比例需要显着的管理实现了有针对性的低迷和延缓AA轻质矿渣混凝土的坍落度损失
在本研究中，所有轻量级和五个轻质砂AA矿渣混凝土混合物和易性，力学性能，混凝土的收缩应变进行了测试，以评估水含量的影响。与实证模型，提出由美国混凝土协会（ACI）209（ACI的19941），体重正常的硅酸盐水泥混凝土抗压强度发展与收缩应变率进行了测量和比较。检查轻量级AA矿渣混凝土劈裂抗拉强度和弹性模量和记录的混凝土试件的破裂的实用性，通过各种渠道为轻量级的OPC混凝土，尽可能预测值进行比较。
实验细节
物料
被激活的粒化高炉矿渣（微粉）由硅酸钠（氧化钠•二氧化硅）和氢氧化钙的[Ca（OH）2粉末和作为胶凝粘结剂使用。用于材料的来源，矿粉高CaO含量2.29质量和二氧化硅，氧化铝的比例。矿粉测量比重比表面积，分别为2.2和4200。使用硅酸钠粉50.2％氧化钠和45％的氧化硅的化合物，生产的摩尔比为0.9，其中氢氧化钙粉末的纯度为95.8％。
高强度的AA矿粉混凝土使用液态钠的摩尔比1至1.5硅酸盐。由粘结剂，包括矿渣粉和碱活化剂，硅酸钠到矿粉的氧化钠的氢氧化钙的重量比例为7.5％和3％以上，分别为，以方便矿粉之间的硅酸盐阴离子和碱性活化的阳离子通过离子交换的化学反应。因此，被选中的氢氧化钙胶比为7.5％和钠硅酸盐加入氧化钠的，矿粉比为3％，生产水泥的AA渣粘结。
人为扩大的最大尺寸为19毫米和5毫米的粘土颗粒轻质粗，细骨料，分别用于。体重正常的细骨料也可用于本地最大粒径5毫米的天然砂。从X射线衍射测量，轻骨料的主要成分是石英和钙铝硅酸盐。图1所示，轻质骨材是球形的形状与封闭表面略显粗糙的质感。粒子的核心有一个统一的罚款和多孔结构，导致高隔热和隔音，但引起的高吸水性和低强度。特别是水轻集料的吸收率是非常快的轻质骨材在第3小时，然后吸收速度减慢，如图2所示。和图所示的物理性能和使用总量的颗粒分布。 3，分别。使用轻质骨材的比重约为2.5倍，比天然砂低，吸水率高得多，而在轻骨料计量比天然砂。轻骨料粒度分布呈连续分级，满足分布在韩国工业标准规范（韩国标准信息中心20068）建议的标准曲线，作为绘制在
图1
塑造和扫描电子显微镜（SEM）照片使用的轻质粗总
图2
水的使用总量的吸收率
图3
所使用的聚合粒子分布曲线：（一）轻质骨材;（二）体重正常的集合体（天然砂）
混合比例
五轻量级和五沙轻量级AA矿渣混凝土混合制备了不同的单位体积混凝土的水分含量，如表2给出。高水胶比可以导致隔离轻质混凝土（ACI的19982）。此外，在本研究有针对性的轻量级AA矿渣混凝土抗压强度大于24兆帕的应用结构混凝土构件。从不同的初步测试，按重量和体积的细骨料合计比水胶比固定为30％和40％，分别在所有混凝土混合料轻骨料和天然砂，挫伤24小时，然后风干24 h，以模拟饱和面干状态，常用于预拌混凝土厂雇用。碱性粘结剂和骨料在1分钟的泛搅拌机干混，然后水被添加并混合另1分。对于所有混凝土混合料，基于聚碳酸酯减水剂与引气剂的混合物增加了0.5％，相对的粘结剂用量。最初的低迷后进行了测试，每个混合倒入各种模具钢材来衡量的抗压强度和其它机械性能。后立即铸造，所有标本在室温下固化，直至在指定年龄的测试。
混合，固化，测试
轻骨料和天然砂，挫伤24小时，然后风干24 h，以模拟饱和面干状态，常用于预拌混凝土厂雇用。碱性粘结剂和骨料在1分钟的泛搅拌机干混，然后水被添加并混合另1分。对于所有混凝土混合料，基于聚碳酸酯减水剂与引气剂的混合物增加了0.5％，相对的粘结剂用量。最初的低迷后进行了测试，每个混合倒入各种模具钢材来衡量的抗压强度和其它机械性能。后立即铸造，所有标本在室温下固化，直至在指定年龄的测试。
测试结果和讨论
初始坍落度和坍落度损失
初始坍落度，硅轻量级AA矿渣混凝土，增加水含量的增加，这是一般轻量级的OPC混凝土的观察以及（内维尔19959）。在相同的含水量，所有轻量级AA矿渣混凝土表现出更高的价值比沙轻量级AA矿渣混凝土初始坍落度，如表3所示。轻质骨材相对圆滑的表面质地，初步改善混凝土和易。
急剧下降的不景气，S的混凝土，测试所用的时间，这表明，一个更加显着的所有轻量级AA矿渣混凝土的坍落度损失比轻质砂AA矿渣混凝土，如图所示 4。混凝土坍落度没有记录标本-150-165，90分钟后的S-135和标本-180和120分钟，因为快速设定时间的S-150。轻质骨材水吸收率高，如图所示 2，硅酸钠的快速反应，导致快速设置在混凝土，轻质混凝土在60分钟后混合在165 kg/m3的水含量，可以衡量，没有不景气。然而，水分含量的增加，缓解了混凝土试件的坍落度损失。这可能是由于含水量增加，导致在混在混凝土轻质骨材量的减少和增加自由水之间的水合凝胶。从图 4，相对低迷，轻量级AA矿渣混凝土的S /硅，可以近似表示为KT +1方面所用的时间，而S是在指定的时间，混合后的不景气，硅混合后立即初始坍落度（ 0分），T是经过时间以分钟为单位，k为线性回归分析，可以从获得的坍落度损失率。因此，基于非线性多元回归分析考虑的含水量，WV，轻骨料，LAV，钙激活轻质矿渣混凝土，坍落度损失率，K（OH）2量的影响和Na2O•SiO2的可以以下形式表示，如在图5：
图4
相对低迷，对所用的时间：（一）轻质混凝土;（b）砂重量
图
5
一般的OPC混凝土抗压强度的发展作为一个抛物线函数模拟，抗压强度发展的速度越来越快，随着年龄的增加而降低。 ACI209（ACI的19941），随着年龄的增长提出以下形式的水泥混凝土抗压强度发展：
FC“（T）=抗压强度年龄t（天）。常量的A1和B1式。 （2）一般在幼年和长期的年龄，分别涉及到的开发实力。在A1和B1的值越低，特别是在早期和长期的年龄表明抗压强度发展率较高，分别为。测试发生在一个抛物线形状的混凝土抗压强度发展，如图所示7，常量A1和B1式的测试结果。 （2）非线性回归分析使用SPSS软件，即相关系数为0.96以上所有的混凝土试件得到确定。
图6
典型的轻量级AA矿渣混凝土抗压强度发展
图绘制的常量A1和B1，从测试的具体确定。在相同的数字，在ACI 209（ACI的19941）水泥混凝土指定的两个常量进行比较。从小在轻量级AA矿渣混凝土的强度增益是非常迅速，这表明，在1天抗压强度达到高于75％的28天抗压强度高。因此，不断为AA矿渣混凝土轻质A1的低于的OPC混凝土高早强水泥混凝土蒸汽下治愈，如图所示 8。轻骨料和快速形成水合凝胶的水吸收率高，可以导致更高的强度发展，在早期的年龄。此外，不断为AA矿渣混凝土轻质B1的接近到1.0，这是类似于早期强度高下蒸汽固化的硅酸盐水泥混凝土的价值观，无论含水量。总的来说，AA轻质矿渣混凝土抗压强度的发展速度，在室温下固化，蒸汽固化早强硅酸盐水泥混凝土相比，如下图所示 7。在潮湿状态下的轻骨料，有一个有利的影响，在长期的年龄上，因为释放水分饱和的集合体，它通常被称为自体固化效果（柯林斯和Sanjayan 19995）连续水化强度发展。虽然没有显着的自体固化效果观察轻量级AA矿渣混凝土试件，获得了一个稳定的强度增益，在长期的年龄，如图所示
图7
典型的轻量级AA矿渣混凝土抗压强度发展
图绘制的常量A1和B1，从测试的具体确定。8。在相同的数字，在ACI209（ACI的19941）水泥混凝土指定的两个常量进行比较。从小在轻量级AA矿渣混凝土的强度增益是非常迅速，这表明，在1天抗压强度达到高于75％的28天抗压强度高。因此，不断为AA矿渣混凝土轻质A1的低于的OPC混凝土高早强水泥混凝土蒸汽下治愈，如图所示
图8
弹性模量，断裂
建议的断裂模数，FR，干腌的轻量级OPC混凝土最佳配备为0.35。 FR是轻质混凝土和轻质砂混凝土0.527 0.465，如图所示的ACI 318-08（ACI的20083）指定。 10。有没有在欧洲法典2“（BSI 20044）FR规定。表5提供了一个轻量级机管局具体的测量和预测FR之间的比较。阻燃效果的含水量在FSP指出，类似。降低界面裂纹之间的聚合和含水量增加引起膏，可以提高混凝土的抗拉。此外，FR轻量级AA矿渣混凝土高于板岩等建议的经验公式预测。 （198613），但同意与预测的ACI 318-08（ACI的20083）
结论
以评估结构安全和轻量级AA具体的实际应用，具体需要进行审查，根据不同的参数和与代码规定的OPC混凝土的各项力学性能混凝土的和易性和力学性能，粘结剂和骨料，以及混合比例的特点。此外，应该提出的经验公式，预测AA轻质混凝土的力学性能，广泛的测试数据的基础上，要考虑各种影响因素。因此，有必要收集关于AA轻质混凝土的各种性能的实验数据，根据组合条件的变化，轻量级机管局矿渣混凝土标本和从经验公式和一个轻量级的OPC混凝土的数据库得到的预测与实验结果进行比较试验的基础上，可以得出以下结论：
1.1
混凝土坍落度测试急剧下降，在经过时间显示，所有轻量级AA矿渣混凝土在轻质砂AA矿渣混凝土坍落度损失比发达国家更加显着。然而，水含量的增加，缓解了轻量级AA矿渣混凝土的坍落度损失。
2.2
随着水分的增加，轻量级AA矿渣混凝土抗压强度略有增加，呈现出AA矿渣混凝土轻质砂高于所有轻量级AA矿渣混凝土的强度。此外，指出，在轻量级的OPC混凝土抗压强度增加对轻量级AA矿渣混凝土的干密度率是类似的。
3.3
轻量级AA矿渣混凝土的压缩强度在室温下固化的发展速度与蒸汽固化早强硅酸盐水泥混凝土。
4.4
劈裂抗拉强度和破裂及轻量级AA矿渣混凝土的弹性模量，较轻量级OPC混凝土的更好，结果是，他们可以保守评估用板岩等实证模型。
5.5
奔放收缩应变的AA矿渣混凝土轻质线性增加，直到14天的年龄，仍然几乎保持不变，直到28天之后，再次大幅度增加。总的来说，收缩应变从轻量级AA矿渣混凝土试件测量大于在ACI209（ACI的19941）指定在早期经过40天的龄期和经验模型的预测，不管它的含水量。
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