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混凝土氯离子扩散系数检测技术规程一、前言混凝土氯离子扩散系数检测是评估混凝土耐久性能的重要手段。
本技术规程旨在指导混凝土氯离子扩散系数检测的操作流程、方法和要求，确保检测结果准确可靠，为混凝土相关工程提供参考。
二、设备与试剂1. 混凝土氯离子扩散系数检测仪器：常用的仪器有NT Build 492、JTG E51-2006、ASTM C1202等，选择仪器应考虑设备的精度、灵敏度、易用性和稳定性等因素。
2. 电极：采用银-银氯化物电极。
3. 氯化钙试剂：纯度不低于95%。
三、实验室条件1. 实验室应保持稳定的温度（20℃±5℃）和相对湿度（50%±10%）。
2. 实验室应有良好的通风系统，以避免气体积聚和对检测结果的影响。
3. 实验室应有充足的光源和配备不同波长的光谱仪器以检测氯化物离子。
四、样品采集和制备1. 样品应采自混凝土结构中代表性的位置，如柱子、梁、板等。
2. 采样前应对混凝土表面进行清洁，以避免表面附着物对结果的影响。
3. 样品的尺寸应根据检测仪器的要求进行裁剪，并保证样品的表面光滑平整。
4. 样品宜在采样后尽快进行检测，否则应在恒温恒湿条件下保存以避免样品干燥和变形等问题。
五、检测过程1. 样品应在检测前进行干燥处理，并记录干燥后的质量和厚度。
2. 将样品放置于检测仪器中，注入氯化钙试剂，并启动检测程序。
3. 检测时间应根据样品的类型、尺寸、厚度和检测仪器的要求进行设置。
4. 检测结束后，取出样品，重新称重并记录质量。
5. 计算氯离子扩散系数。
六、数据处理与分析1. 按照检测仪器的说明书，将检测结果转化为氯离子扩散系数。
2. 根据实际情况，对检测结果进行统计和分析，绘制相关曲线以评估混凝土的耐久性能。
3. 在数据处理过程中，应注意避免误差的积累和数据异常的影响。
七、质量控制1. 定期对检测仪器进行校准和维护，确保设备的稳定性和精度。
2. 对样品进行标准化处理，以保证样品的一致性和可比性。
氯离子扩散系数和混凝土性质实验报告实验报告：氯离子扩散系数和混凝土性质摘要：本实验通过测定不同混凝土中氯离子的扩散系数，研究了混凝土中氯离子的渗透特性及其对混凝土性质的影响。
实验结果表明，混凝土的抗渗性能与其氯离子扩散系数呈负相关关系。
这一研究有助于加深对混凝土结构中氯离子渗透的认识，提高混凝土工程质量。
关键词：氯离子扩散系数；混凝土；抗渗性能；混凝土工程质量一、引言混凝土是一种常见的建筑材料，广泛用于建筑结构的搭建。
然而，由于混凝土的多孔性和渗透性，氯离子等有害物质容易渗透进混凝土内部，导致混凝土的性能下降和寿命缩短。
因此，研究混凝土中氯离子的扩散系数及其对混凝土性质的影响对于提高混凝土工程质量具有重要的意义。
二、实验目的1.测试不同混凝土中氯离子的扩散系数；2.分析混凝土中氯离子的渗透特性；3.探讨氯离子扩散系数与混凝土抗渗性能的相关性。
三、实验方法1.实验材料准备选取三种不同配比的混凝土样品，分别记为A、B、C。
混凝土样品的配比见表1表1混凝土样品配比样品水泥砂水石子A3008002001000B3506501801200C40060016014002.实验步骤（1）制备混凝土样品：按照表1的配比将水泥、砂、水和石子混合搅拌，并将混合物倒入模具中，在模具中振实，然后在室温下养护7天。
（2）测量氯离子扩散系数：首先将混凝土样品切割成大小为5cm×5 cm×5 cm的立方体，然后将其浸泡在含氯离子的水溶液中，经过一定时间后取出，使用离子选择性电极测量氯离子的浓度变化，并绘制出浓度随时间变化的曲线。
（3）分析数据：根据实验数据计算不同混凝土中氯离子的扩散系数。
同时，根据实验结果分析氯离子扩散系数与混凝土抗渗性能的相关性。
四、实验结果与讨论1.氯离子渗透特性实验结果表明，不同混凝土中氯离子的渗透速率存在差异。
在相同时间内，样品C中的氯离子浓度变化最大，说明该样品的渗透性能最差；样品B中的氯离子浓度变化次之；样品A中的氯离子浓度变化最小，说明该样品的渗透性能最好。
混凝土标准氯离子扩散系数要求一、前言混凝土是现代建筑中最常用的材料之一，其性能直接影响着建筑的使用寿命和安全性能。
氯离子扩散是混凝土中常见的一种现象，会导致混凝土表面出现裂缝、腐蚀等问题，进而影响混凝土的使用寿命。
因此，混凝土标准中对氯离子扩散系数的要求非常重要。
本文将从混凝土标准中对氯离子扩散系数的要求进行全面的详细解析，包括标准的概述、氯离子扩散系数的定义、测试方法和标准要求等方面。
同时，也将对氯离子扩散系数的相关知识进行简单介绍，以便读者更好地理解标准要求。
二、概述混凝土的氯离子扩散系数是指氯离子在混凝土中扩散的速率，是评价混凝土耐久性能的一个重要指标。
氯离子扩散系数越小，混凝土的耐久性能越好。
在混凝土标准中，对氯离子扩散系数的要求主要包括测试方法和标准值。
测试方法包括静态浸泡法和电导率法，标准值则根据混凝土的使用环境和等级不同而有所差异。
三、氯离子扩散系数的定义氯离子扩散系数是指氯离子在混凝土中扩散的速率，通常用D表示，单位为mm²/s。
其计算公式如下：D = M / (CtS)其中，M为被扩散物质在时间t内透过单位面积的质量，C为混凝土中被扩散物质的初始浓度，S为混凝土试件的厚度。
氯离子扩散系数的大小取决于混凝土的孔隙结构和渗透性能，一般来说，混凝土的密实度越高，孔隙度越小，氯离子扩散系数就越小。
四、测试方法混凝土中氯离子扩散系数的测试通常采用静态浸泡法和电导率法两种方法。
1.静态浸泡法静态浸泡法是指将混凝土试件浸泡在含氯离子的水中，通过测量水中氯离子浓度的变化来计算氯离子扩散系数。
具体操作步骤如下：（1）制备混凝土试件，并在试件表面涂上防水剂；（2）将试件放入含氯离子的水中，保持一定的浸泡时间；（3）取出试件后，用水洗净表面的防水剂；（4）测量水中氯离子浓度的变化，计算氯离子扩散系数。
2.电导率法电导率法是指通过测量混凝土试件中氯离子的电导率来计算氯离子扩散系数。
具体操作步骤如下：（1）制备混凝土试件，并在试件表面涂上防水剂；（2）将试件放入含氯离子的水中，保持一定的浸泡时间；（3）取出试件后，用水洗净表面的防水剂，然后测量试件中氯离子的电导率；（4）根据电导率计算氯离子扩散系数。
混凝土中氯离子扩散系数的测试方法混凝土中氯离子扩散系数是评估混凝土结构耐久性的重要指标之一。
本文将介绍混凝土中氯离子扩散系数的测试方法。
一、原理混凝土中氯离子扩散系数测试是基于氯离子在混凝土中扩散的原理进行的。
氯离子在混凝土中的扩散可以用菲克第一定律表示：$$I=-D\frac{dc}{dx}$$其中，$I$为氯离子的扩散通量，$D$为氯离子的扩散系数，$c$为混凝土中氯离子的浓度，$x$为扩散距离。
在实验室中，可以通过浸泡试验或扩散试验来测定混凝土中氯离子的扩散系数。
浸泡试验是将混凝土试块浸泡在含有氯离子的溶液中，通过测定溶液中氯离子的浓度变化来评估混凝土中氯离子的扩散系数。
扩散试验是将混凝土试块的一侧暴露在含有氯离子的溶液中，通过测定混凝土试块对侧的氯离子浓度变化来评估混凝土中氯离子的扩散系数。
二、试验设备1. 氯离子浸泡试验设备：搅拌器、恒温水槽、电子天平、浸泡模具、试块钳、氯离子电极、电位计。
2. 氯离子扩散试验设备：搅拌器、电子天平、扩散模具、试块钳、氯离子电极、电位计。
三、试验步骤1. 混凝土试块的制备制备代表性的混凝土试块，试块尺寸为100mm×100mm×100mm。
混凝土材料应当符合设计要求，按照设计配合比进行配合。
2. 氯离子浸泡试验（1）试块表面处理：在试块表面切割出一个6cm×6cm的平面区域，用无菌棉球擦拭干净。
（2）制备浸泡溶液：将0.3M NaCl溶液配制在恒温水槽中，控制温度在23±2℃。
（3）试块浸泡：将试块放置在浸泡模具中，模具中加入浸泡溶液，深度为试块高度的1/2。
试块浸泡时间为28天。
（4）测量氯离子浓度：浸泡28天后，取出试块，用无菌棉球擦干表面水分，然后在试块上切割出一个6cm×6cm的平面区域，取样3次，每次样品重复3次，用氯离子电极测定浸泡溶液中氯离子的浓度。
（5）计算氯离子扩散系数：根据测量结果，计算出混凝土中氯离子的扩散系数。
混凝土氯离子扩散系数测试标准一、前言混凝土氯离子扩散系数测试是评估混凝土抗氯离子侵蚀性能的重要指标之一。
该测试方法对于混凝土结构的设计、施工、养护以及维修等环节都具有重要的意义。
本文旨在制定一套全面详细的混凝土氯离子扩散系数测试标准。
二、适用范围本标准适用于评估混凝土的氯离子扩散系数，该系数可用于评估混凝土的耐久性能，包括混凝土的材料性能、设计、施工和养护等方面。
三、测试原理混凝土氯离子扩散系数测试是通过对混凝土中氯离子扩散的速率进行测量，来评估混凝土的抗氯离子侵蚀性能。
该测试方法基于离子扩散理论，通过测量混凝土中氯离子的扩散系数，来评估混凝土的抗氯离子侵蚀性能。
四、设备和试剂1. 混凝土样品：规格为100mm×100mm×100mm的立方体混凝土样品。
2. 氯化钠溶液：质量浓度为5%的氯化钠溶液。
3. 水：纯净水。
4. 氯离子扩散测试仪：包括钢模具、电极、电源等。
5. 恒温水槽：温度控制范围为20℃~30℃。
6. 称量器：精度为0.1g。
7. 研钵：用于混合试剂。
8. 研钵刷：用于清洗研钵。
9. 吸水纸：用于吸水混凝土表面的水分。
10. 灌胶机：用于密封混凝土表面。
11. 坩埚：用于烧制混凝土样品。
12. 恒温器：用于控制烧制温度。
五、试验步骤1. 样品制备将混凝土样品按照规格切割成100mm×100mm×100mm的立方体样品，并在样品表面用水吸水纸吸干表面水分，待表面干燥后，用灌胶机将样品四周密封。
2. 测量混凝土密度将样品放入坩埚中，将坩埚放入恒温器中，以800℃的温度烧制4小时。
待样品冷却后，用称量器称量样品质量，计算出混凝土密度。
3. 测量混凝土氯离子扩散系数（1）将混凝土样品放入恒温水槽中，保持温度在20℃~30℃之间。
（2）将氯化钠溶液注入电极中，将电极插入混凝土样品中心，开启电源，记录氯离子扩散时的电流强度。
（3）根据实验数据计算混凝土氯离子扩散系数。
混凝土的抗氯离子渗透性标准一、前言混凝土是建筑工程中最常见的材料之一，其主要成分为水泥、砂、石等。
在建筑工程中，混凝土的主要功能是承受和传递结构的荷载，因此混凝土的性能直接影响建筑物的安全性和耐久性。
而氯离子渗透是混凝土耐久性的重要指标之一，因此确定混凝土抗氯离子渗透性标准对于保证建筑物的耐久性和安全性至关重要。
二、混凝土的抗氯离子渗透性氯离子是混凝土中最常见的有害离子之一，它可以进入混凝土内部并与水泥中的氢氧化钙反应，形成氯化钙，导致混凝土的物理性能和力学性能下降，从而影响建筑物的耐久性和安全性。
因此，要保证混凝土的耐久性和安全性，必须控制混凝土中氯离子的渗透。
混凝土抗氯离子渗透性是指混凝土对氯离子渗透的阻力能力，通常用氯离子扩散系数来衡量。
氯离子扩散系数是指单位时间内氯离子在混凝土中扩散的距离，它与混凝土中氯离子浓度、孔隙度、孔径分布等因素有关。
一般来说，混凝土的孔隙度和孔径分布越小，氯离子扩散系数就越小，抗氯离子渗透性就越好。
三、混凝土抗氯离子渗透性标准1. 混凝土氯离子扩散系数混凝土氯离子扩散系数是反映混凝土抗氯离子渗透性的重要指标之一。
国内外对混凝土氯离子扩散系数的标准不尽相同，但一般都要求混凝土的氯离子扩散系数小于某个特定值。
例如，美国ACI 318-14标准规定，混凝土氯离子扩散系数应小于1.0x10^-12 m^2/s；欧洲标准EN 206-1则规定，混凝土氯离子扩散系数应小于1.0x10^-12 m^2/s。
2. 混凝土的抗氯离子渗透等级混凝土的抗氯离子渗透等级是指混凝土对氯离子渗透的阻力等级，通常用P值来表示。
P值是氯离子扩散系数与混凝土厚度的比值，它反映混凝土对氯离子渗透的抵抗能力。
一般来说，P值越大，混凝土的抗氯离子渗透性就越好。
国内对混凝土抗氯离子渗透等级的标准是GB/T 50082-2009《混凝土结构耐久性设计规范》，其中将混凝土抗氯离子渗透性分为四个等级，分别为P8、P10、P12、P15。
ASTM C1556-03使用容积扩散法测定胶结混合剂表观氯化物扩散系数的试验方法1本标准发布在固定标识号C1556下；紧接着标识号后面的数字表示的最初收录的年份或在修订的情况下，最后一次修订的年份。
括号中的数字表示最新重新批准的年份。
上标（ε）表示自上次修订或重新审批的编辑修改。
1.范围1.1 本测试方法涵盖了实验室测定胶结混合剂表观氯化物扩散系数。
1.2 SI规定的值被视为标准。
1.3 这个标准并不解决所有的主旨安全问题，如果有的话,与其使用相关。
这是此标准的用户的责任，建立适当的安全与健康行为，在使用前确定监管限制的适用性。
2.参考文献2.1 美国材料试验协会标准C 31/C 31M Practice for Making and Curing Concrete Test Specimens in the Field2C 42/C 42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete2C 125 Terminology Relating to Concrete and Concrete Aggregates2C 192/C 192M Practice for Making and Curing Concrete in the Laboratory2C 670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials2C 1152/C 1152M Test Method for Acid-Soluble Chloride in Mortar and Concrete2C 1202 Test Method for Electrical Indication of Concrete’s Ability to Resist Chloride-ion Penetration22.1 北欧测试合作组织标准NT BUILD 443, Approved 1995-11, Concrete, Hardened:Accelerated Chloride Penetration (in1这种测试方法是在ASTM委员会C09关于混凝土和混凝土集料课题管辖下的，是小组委员会C09.66关于混凝土抵抗液体渗透课题直接责任的。
混凝土的氯离子扩散性分析混凝土是一种常见的建筑材料，广泛应用于各种工程中。
然而，由于氯离子对混凝土的侵蚀性较强，如果混凝土中存在氯离子的渗透问题，将会导致混凝土的腐蚀和破坏，从而影响建筑物的使用寿命。
因此，分析混凝土的氯离子扩散性非常重要。
本文将从氯离子扩散机理、实验方法以及评估氯离子扩散性的指标等方面进行探讨。
一、氯离子扩散机理混凝土中的氯离子主要通过孔隙结构扩散。
当混凝土内部湿度较高，氯离子和水分子将沿着浓度梯度通过孔隙的间隙进行扩散。
扩散过程中，氯离子与水分子间的碰撞及周围材料的阻力会影响扩散速率。
此外，混凝土的孔隙结构也对氯离子的扩散起着重要作用。
孔隙连通性的增加和孔径的增大都会导致氯离子的扩散加快。
二、实验方法为了准确评估混凝土中氯离子的扩散性，需要进行一系列的实验。
下面介绍几种常用的实验方法。
1. 水浸法（ASTM C1202）水浸法是一种用于评估混凝土氯离子渗透性能的标准测试方法，常用于工程质量检验。
该方法通过测量混凝土试件电流的变化，进一步计算氯离子的电荷量来评估氯离子的扩散性能。
实验结果以表观氯离子扩散系数表示。
2. 氯离子渗透试验（ASTM C1556）氯离子渗透试验是一种更加直接的方法，用于测量混凝土中氯离子的渗透深度。
试验时，在混凝土表面涂覆氯化钠溶液，通过重量法或化学分析法测定氯离子的渗透深度。
实验结果可用于评估混凝土的抗渗性能。
三、评估氯离子扩散性的指标了解混凝土的氯离子扩散性能，需要依据一些指标进行评估。
1. 表观氯离子扩散系数表观氯离子扩散系数是衡量混凝土中氯离子扩散速率的重要指标。
它可以通过水浸法等实验方法得到，一般以立方米/秒（m²/s）为单位。
表观氯离子扩散系数越大，表示混凝土的氯离子扩散速率越快。
2. 渗透深度渗透深度是使用氯离子渗透试验测得的指标，用于评估混凝土中氯离子的渗透性能。
渗透深度越大，说明混凝土的抗渗性能越差。
3. 氯离子浓度分布曲线氯离子浓度分布曲线可以通过化学分析方法或电荷量测定方法得到。
混凝土的氯离子扩散系数检测标准一、前言混凝土结构是现代建筑中最常见的结构之一，其在建筑物中承担着重要的结构和功能。
然而，混凝土结构在长期使用中，受到各种外力和环境的影响，会发生各种损伤和病害，其中混凝土的氯离子渗透是导致混凝土结构损坏的主要原因之一。
因此，对混凝土的氯离子扩散系数进行检测和评估，对于延长混凝土结构的使用寿命具有重要意义。
二、氯离子扩散系数的定义氯离子扩散系数是指单位时间内，氯离子在混凝土中扩散的距离与混凝土中氯离子浓度梯度之比，通常用m2/s表示。
氯离子在混凝土中的扩散是一个复杂的过程，受到多种因素的影响，包括混凝土配合比、水灰比、孔隙结构、温度、相对湿度、氯离子浓度等。
三、氯离子扩散系数的检测方法氯离子扩散系数的检测方法主要有以下几种：1. 氯离子电导法：该方法基于氯离子在混凝土中的电导性质，通过测量混凝土样品中氯离子的电导率，计算出氯离子扩散系数。
2. 滴定法：该方法是将混凝土样品放置在饱和氯化钠溶液中浸泡一段时间，然后取出样品，用盐酸滴定法测定浸泡液中氯离子的含量，计算出氯离子扩散系数。
3. 荧光法：该方法是在混凝土表面涂上一层荧光涂料，然后在荧光显微镜下观察混凝土中氯离子的扩散情况，根据荧光强度的变化，计算出氯离子扩散系数。
4. 氯离子荧光探针法：该方法是将氯离子荧光探针溶液浸渍到混凝土表面，然后使用激光扫描显微镜观察荧光信号的变化，计算出氯离子扩散系数。
四、氯离子扩散系数的检测标准氯离子扩散系数的检测标准主要有以下几个方面：1. 样品制备：混凝土样品应选择充分代表混凝土结构的部位进行采样，样品制备应符合相关标准要求。
2. 检测方法：应选择合适的检测方法进行氯离子扩散系数的测定，检测方法应符合相关标准要求。
3. 检测条件：检测条件包括温度、相对湿度、氯离子浓度等，应符合相关标准要求。
4. 数据处理：应按照相关标准要求对检测数据进行处理和分析，确定氯离子扩散系数的大小和变化趋势。
混凝土的氯离子扩散系数检测标准一、前言混凝土是建筑工程中常用的材料，其性能对工程质量和使用寿命有着直接的影响。
混凝土中的氯离子是导致混凝土钢筋锈蚀的主要原因之一，因此对混凝土中氯离子的扩散系数进行检测具有重要的意义。
本文将介绍混凝土的氯离子扩散系数检测标准。
二、混凝土的氯离子扩散系数混凝土中的氯离子可通过水泥基体的孔隙结构向外扩散，当氯离子浓度超过一定的阈值时，将导致混凝土的钢筋锈蚀和混凝土的损坏。
因此，混凝土的氯离子扩散系数是衡量混凝土耐久性的一个重要指标。
混凝土的氯离子扩散系数可通过实验测定得到，一般采用荧光分析法、重量损失法、电化学方法等进行测定。
三、混凝土的氯离子扩散系数检测标准1. 检测设备要求混凝土的氯离子扩散系数检测设备应具有以下要求：（1）温度控制精度应达到±1℃；（2）荧光分析法设备应具有高分辨率、高灵敏度的特点；（3）重量损失法设备应具有高精度的天平和恒温恒湿的环境控制系统；（4）电化学方法设备应具有高精度的电位计和电极。
2. 检测样品要求混凝土的氯离子扩散系数检测样品应符合以下要求：（1）样品的尺寸应足够大，以保证测试结果的准确性；（2）样品应符合设计要求，具有代表性；（3）样品的表面应平整，无明显的缺陷和裂缝。
3. 检测方法要求（1）荧光分析法荧光分析法是一种常用的混凝土氯离子扩散系数测定方法。
该方法通过荧光分析仪对荧光强度进行测试，进而计算出氯离子的扩散系数。
具体操作步骤如下：① 准备样品，将混凝土样品切成尺寸相同的试件；② 在样品表面涂上荧光探针；③ 确定测试温度和湿度；④ 测定荧光强度，并计算出氯离子的扩散系数。
（2）重量损失法重量损失法是一种直接测量氯离子扩散深度的方法。
该方法通过测量样品的质量变化来计算氯离子的扩散系数。
具体操作步骤如下：① 准备样品，将混凝土样品切成尺寸相同的试件；② 在样品表面涂上一层防水涂料；③ 确定测试温度和湿度；④ 将样品浸泡在含氯离子的溶液中，测定样品质量的变化，并计算出氯离子的扩散系数。
Designation:C 1556–04Standard Test Method forDetermining the Apparent Chloride Diffusion Coefficient of Cementitious Mixtures by Bulk Diffusion 1This standard is issued under the fixed designation C 1556;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon (e )indicates an editorial change since the last revision or reapproval.1.Scope*1.1This test method covers the laboratory determination of the apparent chloride diffusion coefficient for hardened cemen-titious mixtures.1.2The values stated in SI units are to be regarded as the standard.1.3This standard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents 2.1ASTM Standards:2C 31/C 31M Practice for Making and Curing Concrete Test Specimens in the FieldC 42/C 42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of ConcreteC 125Terminology Relating to Concrete and Concrete AggregatesC 192/C 192M Practice for Making and Curing Concrete in the LaboratoryC 670Practice for Preparing Precision and Bias Statements for Test Methods for Construction MaterialsC 1152/C 1152M Test Method for Acid-Soluble Chloride in Mortar and ConcreteC 1202Test Method for Electrical Indication of Concrete’s Ability to Resist Chloride Ion Penetration 2.2NORDTEST Standards:NT BUILD 443,Approved 1995-11,Concrete,Hardened:Accelerated Chloride Penetration (in English)33.Terminology 3.1Definitions :3.1.1For definitions of terms used in this test method,refer to Terminology C 125.3.2Definitions of Terms Specific to This Standard:3.2.1apparent chloride diffusion coeffıcient,D a ,n —a chlo-ride transport parameter calculated from acid-soluble chloride profile data obtained from saturated specimens exposed to chloride solutions,without correction for chloride binding,that provides an indication of the ease of chloride penetration into cementitious mixtures.3.2.2chloride binding ,v —the chemical process by which chloride ion is removed from solution and incorporated into cementitious binder hydration products.3.2.2.1Discussion —Chloride binding is primarily associ-ated with hydration products formed by the aluminate phase of cement and mixtures containing ground granulated blast fur-nace slag.3.2.3chloride penetration ,v —the ingress of chloride ions due to exposure to external sources.3.2.4exposure liquid ,n —the sodium chloride solution in which test specimens are stored prior to obtaining a chloride profile.3.2.5exposure time ,n —the time that the test specimen is stored in the solution containing chloride ion.3.2.6initial chloride-ion content,C i ,n —the ratio of the mass of chloride ion to the mass of concrete for a test specimen that has not been exposed to external chloride sources.3.2.7profile grinding ,v —the process of grinding off and collecting a powder sample in thin successive layers from a test specimen using a dry process.3.2.8surface chloride content,C s ,n —the theoretical ratio of the mass of chloride ion to the mass of concrete at the interface between the exposure liquid and the test specimen.4.Summary of Test Method4.1Obtain a representative sample of the cementitious mixture prior to exposure to chloride ion.Separate each sample into a test specimen and an initial chloride-ion content speci-men.Crush the initial chloride-ion content specimen and determine the initial acid-soluble chloride-ion content.Seal all sides of the test specimen,except the finished surface,with a1This test method is under the jurisdiction of ASTM Committee C09on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.66on Concrete’s Resistance to Fluid Penetration.Current edition approved June 1,2004.Published July 2004.Originally approved in st previous edition approved in 2003as C 1556–03.2For referenced ASTM standards,visit the ASTM website,,or contact ASTM Customer Service at service@.For Annual Book of ASTM Standards volume information,refer to the standard’s Document Summary page on the ASTM website.3Published by NORDTEST,P.O.Box 116FIN-02151ESPOO Finland,Project 1154-94,e-mail:nordtest @vtt.fi,website:http://www.vtt.fi/nordtest1*A Summary of Changes section appears at the end of this standard.Copyright ©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.suitable barrier coating.Saturate the sealed specimen in a calcium hydroxide solution,rinse with tap water,and then place in a sodium chloride solution.After a specified exposure time,the test specimen is removed from the sodium chloride solution and thin layers are ground off parallel to the exposed face of the specimen.The acid-soluble chloride content of each layer is determined.The apparent chloride diffusion coefficient and the projected surface chloride-ion concentration are then calculated using the initial chloride-ion content,and at least six related values for chloride-ion content and depth below the exposed surface.5.Significance and Use5.1This test method is applicable to cementitious mixtureshave not beenexposed to external chloride ions,other than negligible quantity of chloride ion exposure from sample preparation using potable water,prior to the test.5.2The calculation procedure described in this test method is applicable only to laboratory test specimens exposed to a sodium chloride solution as described in this test method.This calculation procedure is not applicable to specimens exposed to chloride ions during cyclic wetting and drying.N OTE 1—The diffusion of ionic species in concrete occurs within the fluid-filled pores,cracks and void spaces.The concentration and valence of other ionic species in the pore fluid also influence the rate of chloride diffusion,and therefore,the apparent diffusion coefficient as determined by this test procedure.5.3In most cases,the value of the apparent chloride diffusion coefficient for cementitious mixtures changes over time (See Note 2).Therefore,apparent diffusion coefficients obtained at early ages may not be representative of perfor-mance in service.N OTE 2—The rate of change of the apparent diffusion coefficient for cementitious mixtures containing pozzolans or blast-furnace slag is typically different than that for mixtures containing only portland cement.5.4The apparent chloride diffusion coefficient is used in Fick’s second law of diffusion to estimate chloride penetration into cementitious mixtures that are in a saturated condition.5.5The apparent chloride diffusion coefficient is commonly used in chloride ingress models based on Fick’s second law of diffusion.The apparent diffusion coefficient determined by this method includes chemically bound chloride,so proper use of the apparent chloride diffusion coefficient to predict chloride ingress requires consideration of chloride binding.5.6The resistance to chloride penetration is affected by such factors as the environment,finishing,mixture composition,workmanship,curing,and age.6.Apparatus6.1Balance ,accurate to at least 60.01g.6.2Thermometer ,accurate to at least 61.0°C.6.3Controlled Temperature Laboratory or Chamber .The laboratory or chamber shall maintain the temperature of a water bath at 2362°C.6.4Plastic Container ,with tight-fitting lid.Select a con-tainer size in accordance with provisions in 9.1.2.6.5Equipment for grinding off and collecting powder from concrete,mortar,or grout specimens in layers of approximately 2mm thickness.Refer to Figs.1and 2for examples of satisfactory equipment (See Note 3).N OTE 3—A lathe or milling machine equipped with a short-barrel carbide-tipped,or diamond-tipped,core drill bit has been found satisfac-tory for profile grinding.6.6Resealable Polyethylene Bags ,200-to 300-mm wide by 250-to 300-mm long,and sheet thickness not less than 0.1mm.6.7Equipment for crushing concrete,mortar or grout.Suit-able equipment is described in Test Method C 1152/C 1152M.6.8Equipment for chloride analysis as described in Test Method C 1152/C 1152M.6.9Slide Caliper ,accurate to at least 60.1mm.7.Reagents and Materials7.1Distilled or De-ionized Water .7.2Calcium Hydroxide [Ca(OH)2],technical grade.7.3Calcium Hydroxide Solution ,saturated,(approx.3g/L).7.4Sodium Chloride [NaCl],technical grade.7.5Exposure Liquid —An aqueous NaCl solution prepared with a concentration of 16561g NaCl per L of solution.7.6Two-component Polyurethane or Epoxy-resin Based Paint ,capable of forming a barrier membrane that is resistant to chloride ion diffusion.8.Test Specimens8.1Drilled cores,molded cylinders,or molded cubes are acceptable test specimens.One sample consists of at least two test specimens representative of the cementitious mixture under test (See Note 4).Specimens must be free of defects such as voids or cracks visible to the unaided eye (See Note 5).The minimum dimension across the finished surface of each test specimen must be at least 75mm,but not less than three times the nominal maximum aggregate particle size.The specimen depth must be at least 75mm.N OTE 4—The material between the exposed surface and the outermost layer of reinforcement is often of interest because it is here that the protection against chloride penetration is needed.Furthermore,the quality of the material in this particular area can deviate from that in the rest of the system,as this region is often affected by construction practices.N OTE 5—Specimens with voids deeper than the profile layer thickness can increase the apparent rate of chloride penetration,and increases test variability.8.2Unless otherwise specified,provide 28days of labora-tory standard moist curing in accordance with Practice C 31/C 31M or C 192/C 192M prior to sample preparation for immersion in the exposure liquid.8.2.1Describe any variance from standard curing practice in the report.8.3For drilled cores obtained according to Test Method C 42/C 42M,prepare the test specimen by cutting off the outermost 75mm of the core.The test specimen thus obtained has one face that is the original finished surface,and the other face that is a sawn surface as shown in Fig.3.8.4For specimens prepared in accordance with Practice C 31/C 31M or C 192/C 192M,the test specimen is prepared by cutting parallel to the finished surface.The top 75mm is used as the test specimen (see Fig.3).8.5From the remainder of the drilled core,or molded specimen,cut a slice that is at least 20-mm e this slice to determine the initial chloride-ion content,C i .8.6Rinse the specimens with tap water immediately after cutting.Scrub the surface with a stiff nylon brush,and rinse again.Prior to sealing specimen surfaces,air dry until no moisture can be removed from the surface with a dry paper towel (See Note 6).8.6.1Exposure specimens must be surface-dry but inter-nally moist prior to sealing.This condition is satisfiedbyFIG.1Profile Grinding Using a MillingMachineFIG.2Profile Grinding Using aLathestandard moist-cured specimens allowed to air dry for no more than 24h in laboratory air maintained at 2362°C and 5063%RH.N OTE 6—Specimens cured in a saturated calcium hydroxide water bath are normally covered by residual lime particles.If this residue is not removed and test specimens are allowed to temporarily dry in air,a calcium carbonate layer can form on the surface of the specimen.This carbonate layer may interfere with the test result,which is why cleansing and rinsing with tap water after cutting or removal from the saturated calcium hydroxide water bath is required.8.7Seal all sides of the exposure specimen except for the finished surface following the procedure described in Test Method C 1202.8.8Determine the initial mass of the test specimen when the coating has hardened.8.9Immerse the test specimen in the saturated calcium hydroxide water bath at 2362°C in a tightly closed plastic container.The container must be filled to the top to prevent carbonation.After 24h of immersion,remove the specimen,blot the surface dry with a paper towel,and determine the mass of the specimen in the surface-dry condition.8.10The test specimen is immersed in a saturated calcium hydroxide water bath until the mass does not change by more than 0.1%in 24h (See Note 7).An acceptable alternative procedure is to vacuum saturate the specimens with saturated calcium hydroxide solution using a vacuum chamber similar to the system described in Test Method C 1202.N OTE 7—Typically,the mass of moist-cured specimens stabilizes within 48h.9.Procedure9.1Exposure :9.1.1Remove the saturated test specimen from the calcium hydroxide water bath,immediately rinse the specimen surface with tap water,place the specimen in the exposure container,fill the container with the exposure liquid,and then seal the container.Place the container in a temperature-controlled chamber or room maintained at 2362°C.Record the start date and start time to the nearest hour.9.1.2It is permitted to place multiple specimens in a single container as long as the specimens are placed in the container such that the entire exposure surface is unobstructed.Maintain the exposed surface area to exposure liquid volume ratio within the range of 50630cm 2/L (See Note 8).N OTE 8—The volume of exposure liquid required for nominal 100-mm diameter cylinder or core exposure specimens is approximately one liter per specimen.9.1.3The specimens must remain in the exposure liquid for at least 35days (See Note 9).N OTE 9—The exposure time should be extended for mixtures such as those that are more mature,were made with low w/cm,or high-performance mixtures containing supplementary cementitious materials.9.1.4If evaporation of water from the exposure liquid or a container leak allows the specimen surface to dry during the exposure time,the test is not valid (See Note 10).N OTE 10—It is suggested to monitor the mass of the sealed container if evaporation of water from the exposure solution is expected.9.1.5Record the exposure time to the nearest hour.9.2Profile Grinding :9.2.1Remove the test specimen from the exposure liquid,rinse with tap water,and dry for at least 24h in laboratory air maintained at 2362°C and 5063%RH.9.2.2When grinding is to be performed longer than 48h after removal from the exposure solution,store the specimens in watertight resealable polyethylene bags until time of grind-ing.When grinding is to be performed longer than 7days after removal from the exposure solution,store the bagged speci-mens in a freezer maintained at -15°C (65°C)until time of grinding.9.2.3Obtain the powder samples by grinding off material in layers parallel to the exposed surface.Do not grind closerthanFIG.3Sketch of Specimens Obtained from a Typical SampleTABLE 1Recommended Depth Intervals (in mm)for Powder Grinding Aw/cm 0.250.300.350.400.500.600.70Depth 10-10-10-10-10-10-10-1Depth 21-21-21-21-31-31-31-5Depth 32-32-32-33-53-53-65-10Depth 43-43-43-55-75-86-1010-15Depth 54-54-65-77-108-1210-1515-20Depth 65-66-87-910-1312-1615-2020-25Depth 76-88-109-1213-1616-2020-2525-30Depth88-1010-1212-1616-2020-2525-3030-35ALuping,Tang and Sørensen,Henrik,“Evaluation of the Rapid Test Methods for Measuring the Chloride Diffusion Coefficients of Concrete,”NORDTEST Project No.1388-98,Swedish National Testing and Research Institute,SP Report 1998:42.N OTE —For cementitious mixtures with pozzolan or slag,the depth intervals in the column one place to the left should be applied.For example,use the depth intervals for w/cm =0.35for silica fume concrete with w/cm =0.40.5mm from the edge of the specimen to avoid edge effects and disturbances from the coating.9.2.4For the minimum exposure time of35days,grind off eight layers in accordance with Table1.For longer exposure times,select depth increments such that a minimum of6points span the range from1mm below the exposed surface to a depth with a chloride-ion content equal to,or slightly greater than, the initial chloride-ion content.9.2.5The following alternate profiling procedure is permit-ted if the exposure time is sufficient to allow chloride penetra-tion deeper than40mm.Slice the test specimen parallel to the exposure surface using a water-cooled diamond saw in5-to6-mm increments,minimizing the time specimens are exposed to water.Dry the slices for24h in laboratory air,then crush and prepare the powder sample as described in Test Method C1152/C1152M.9.2.6Obtain a sample of at least10g of powder from each layer.Determine the distance from the exposure surface to the mid-depth of each layer.For example,the layer thickness and mid-depth are determined from measurements of the specimen before and after powder sample collection.Calculate the depth below the exposed surface as the average offive uniformly distributed measurements using a slide caliper.9.3Chloride Analysis:9.3.1Determine the acid-soluble chloride-ion content of the powder samples,C x(mass%),to60.001%according to Test Method C1152/C1152M.9.3.2Obtain the initial chloride-ion content,C i(mass%), from the20-mm thick slice by crushing and prepare a powder sample as described in Test Method C1152/C1152M.9.4Record any deviations from the requirements of this method.10.Calculations10.1Test Results:10.1.1Determine the values of surface concentration and apparent chloride diffusion coefficient byfitting Eq1to the measured chloride-ion contents by means of a non-linear regression analysis using the method of least squares.Omit the chloride-ion content determined from the exposure surface layer in the regression analysis.All other chloride-ion content measurements are included in the regression analysis.C~x,t!5C s2~C s2C i!·erf S x=4·D a·t D(1)where:C(x,t)=chloride concentration,measured at depth x and exposure time t,mass%,C s=projected chloride concentration at the interfacebetween the exposure liquid and test specimen thatis determined by the regression analysis,mass%, C i=initial chloride-ion concentration of the cementi-tious mixture prior to submersion in the exposuresolution,mass%,x=depth below the exposed surface(to the middle ofa layer),m,D a=apparent chloride diffusion coefficient,m2/s,t=the exposure time,s,anderf=the error function described in Eq2.erf~z!52/=p·*0z exp~2u2!du(2) 10.1.2Tables with values of the error function are given in standard mathematical reference books.4The error function is also included as a library function in most electronic calcula-tion software.10.1.3The test results are:10.1.3.1The initial chloride concentration,C i(mass%), stated to three significant digits.10.1.3.2The projected surface chloride concentration at the exposed surface,C s(mass%),stated to three significant digits.10.1.3.3The apparent chloride diffusion coefficient,D a (m2/s),stated to2significant digits.10.2Non-linear Regression Analysis—Perform the regres-sion analysis by minimizing the sum given in Eq3.Refer to Fig.4for clarification.S5(n52ND C2~n!5(n52N~C m~n!2C c~n!!2(3)where:S=sum of squares to be minimized,(mass%)2,N=the number of layers ground off,D C(n)=difference between the measured and calculatedchloride concentration of the n th layer,mass%, C m(n)=measured chloride concentration of the n th layer,mass%,andC c(n)=calculated chloride concentration in the middle ofthe n th layer,mass%.10.3Other Calculations:10.3.1Plot the measured chloride contents at all points versus depth below the surface.Plot the best-fit curve on the same graph(see Fig.4).11.Report11.1Report the following information if known:11.1.1Name and address of the laboratory,and the place at which tests were performed,if different from the laboratory address.11.1.2Date and identification number of the test report. 11.1.3Method of sampling and other circumstances(date and person responsible for sampling).11.1.4Description of the tested object including specimen type,identification marks,mixture proportions,the date the tested object was cast,curing regimen employed,and age at the start of exposure.11.1.5Start date and duration of the exposure time.11.1.6Conditioning of the test specimens,and a description of the exposure conditions during the test,such as temperature, evidence of evaporation.11.1.7Identification of the test equipment and instruments used.11.1.8Any deviation from the test method together with other information of importance for judging the result.4Beyer,W.H.,ed.,CRC Handbook of Mathematical Sciences,5th Edition,CRC Press,Boca Raton,FL,1978.11.1.9A table listing the chloride-ion content measurements of each layer and mid-depth for each layer.11.1.10A plot showing the measured chloride-ion contents for each layer and the best-fit curve from the regression analysis.11.1.11The measured value of C i and the values of C s ,and D a determined from the regression analysis.11.1.12Date and signature.12.Precision and Bias12.1Precision —There has been no interlaboratory study of this test method.However,there are precision data 5from an interlaboratory study of NORDTEST NT Build 443,from which this test method was developed.The report includes data from two interlaboratory studies involving three concrete mixtures and three to five laboratories participated,depending on the mixture.Average values of D a among the mixtures ranged from 2.1to 14.73(10-12)m 2/s.Average values of C s among the mixtures ranged from 0.61to 1.0%.Table 3summarizes the single-laboratory and multiple-laboratory co-efficient of variation and maximum difference expected be-tween duplicate determinations in 95%of such comparisons.Therefore,the apparent diffusion coefficient results of two properly conducted tests should not differ by more than 39.8%of the mean value.12.2Bias —Since there is no accepted reference material suitable for determining the bias of this test method,no statement on bias is made.13.Keywords13.1chloride;concrete;corrosion;diffusion;ion transport;service life5Luping,Tang and Sørensen,Henrik,“Evaluation of the Rapid Test Methods for Measuring the Chloride Diffusion Coefficients of Concrete,”NORDTEST Project No.1388-98,Swedish National Testing and Research Institute,SP Report1998:42.FIG.4Sample Regression AnalysisTABLE 2Example CalculationC s (mass %)C i (mass %)D a (m 2/s)t (yr)Sum (Error)20.6050.085 4.86E-13 1.00 2.2151E-03x (mm)Measured Value Predicted Value Error,D C (n )(Meas.-Pred.)(Error)210.3680.53020.4500.458-8.19E-03 6.72E-0530.4100.391 1.94E-02 3.76E-0440.3260.329-3.31E-03 1.10E-0550.2660.275-9.49E-039.01E-0560.2310.230 1.25E-03 1.55E-0670.1750.192-1.71E-02 2.93E-0480.1830.162 2.08E-02 4.34E-0490.1320.139-7.07E-03 5.00E-05100.1240.122 2.16E-03 4.66E-06150.1170.089 2.85E-028.12E-04200.0800.085-5.16E-03 2.66E-05250.0780.085-7.00E-034.90E-05TABLE 3Precision Estimates ACoefficientStatistic Single Laboratory Multiple Laboratory D a CV B 14.220.2d2s %39.856.6C sCV 13.318.1d2s %37.250.7AThese statistics represent the CV (1s %)and d2s %statistics as defined in Practice C 670.BCoefficient ofvariation.SUMMARY OF CHANGESCommittee C09has identified the location of selected changes to this test method since the last issue, C1556–03,that may impact the use of this test method.(Approved June1,2004)(2)Freezing requirement added to9.2.2.(1)Added Note1to Significance and Use,increment referencenumbers for all existing notes.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this ers of this standard are expressly advised that determination of the validity of any such patent rights,and the riskof infringement of such rights,are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed everyfive years and if not revised,either reapproved or withdrawn.Your comments 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